TEXT: Codex of the 
  Infinite Planes
  The Essential Guide to the Planes of Existence
  Volume XXI:
  Bleak Eternity of Gehenna
  
  The Essential Guide to the Planes of Existence
  Volume XXI:
  Bleak Eternity of Gehenna
  Written & Designed by  “Weird Dave” Coulson
  DUNGEONS & DRAGONS, D&D, Wizards of the Coast, Forgotten Realms, the dragon ampersand, Player’s Handbook, Monster 
  Manual, Dungeon Master’s Guide, D&D Adventurers League, all other Wizards of the Coast product names, and their respective 
  logos are trademarks of Wizards of the Coast in the USA and other countries. All characters and their distinctive likenesses are 
  property of Wizards of the Coast. This material is protected under the copyright laws of the United States of America. Any repro-
  duction or unauthorized use of the material or artwork contained herein is prohibited without the express written permission of 
  Wizards of the Coast.
  ©2016 Wizards of the Coast LLC, PO Box 707, Renton, WA 98057-0707, USA. Manufactured by Hasbro SA, Rue Emile-Boéchat 31, 
  2800 Delémont, CH. Represented by Hasbro Europe, 4 The Square, Stockley Park, Uxbridge, Middlesex, UB11 1ET, UK.
  Codex of the 
  Infinite Planes
  
  Volume XXI  |  Bleak Eternity of Gehenna
  3
  Volume XXI: Bleak 
  Eternity of Gehenna
  “Greed and an insatiable lust for power dominates the 
  minds of those that seek out Gehenna. The plane is 
  referred to as the Bleak Eternity, though this description 
  does not do it justice – four volcanoes of mind-boggling 
  size dominate each of its layers, from the churning lava 
  heart of Chamada to the icy silence of Krangath. The 
  bleakness comes from the perspective Gehenna forces 
  upon all who tread its mountains layers, that greed and the 
  pursuit of power is the only real goal in the multiverse. Of 
  course, it’s no surprise that the yugoloths who play at being 
  mercenary in the Blood War that rages eternally would 
  find Gehenna a fitting home.”
  Malakara the Warden
  It is said by the poetic among the multiverse that mercy 
  goes to die on the volcanic slopes within the Bleak Eternity 
  of Gehenna. Also known as the Fourfold Furnaces, 
  Gehenna consists of four layers that are each the home 
  to a volcano of staggering size. Most planar scholars 
  believe Gehenna to be the smallest of the Outer Planes, 
  though the lightless void through which the volcanoes 
  drift endlessly is said to have no end, nor any substantial 
  qualities.
  Greed and suspicion walk together on Gehenna, and 
  it has been theorized that the type of evil embodied in 
  the Bleak Eternity is of a fouler and more sinister nature 
  than the Abyss or the Nine Hells. The ideas of personal 
  advancement and self-preservation are not just theoretical 
  ideas here – they are enforced by the environment of 
  Gehenna, which suppresses charity unlike anywhere else 
  in the multiverse. Any helpful act must be inherently selfish 
  in order to succeed in the Fourfold Furnaces, and these 
  acts are viewed by some of the native celestials of the 
  Upper Planes as the greatest evil.
  Physically, Gehenna is a difficult realm that tests 
  visitors and natives alike. The volcanic nature of each 
  layer creates a plane where no flat surface exists naturally. 
  Everything sits on the slope of the layer’s volcano, and the 
  only flat platforms are created artificially by the residents 
  of the plane. Falling is a real hazard, as are rockslides, 
  earthquakes, and poisonous gases, along with volcanic 
  eruptions from the more volatile layers.
  To survive in the Fourfold Furnaces of Gehenna, a 
  person must be willing to push themselves to meet and 
  exceed regular challenges. On the surface, this can 
  be an uplifting and empowering idea, but on Gehenna 
  this concept is perverted with a palpable sense of evil 
  emanating for each volcano’s heart. To exceed, Gehenna 
  whispers, a person must be better than their fellows, and 
  to show mercy is a weakness the plane does not abide.
  Gehenna lacks the raw evil chaos of the Abyss or the 
  militant ordered evil of Baator and relies more on the 
  advancement of the self at the expense of other or lesser 
  creatures. Fiends of all types can be found on the volcanic 
  slopes but none more prevalent than the yugoloths. Many 
  planar scholars believe the yugoloths actually originate 
  from the Gray Wastes of Hades and simply migrated to 
  Gehenna in the distant past, but the origin is moot at this 
  point. Yugoloths are the dominant masters of Gehenna, 
  from the macabre horror of the Crawling City to the 
  countless fortresses, towers, and fortifications built by the 
  mercenary fiends to satiate their personal lust for power.
  There’s an interesting distinction between Gehenna 
  and Carceri as the two planes share miserable traits. 
  Treachery, skullduggery, and backstabbing are common in 
  both, but the difference is in the will of the inhabitants. In 
  Carceri, creatures are trapped, but in Gehenna, they arrive 
  willingly to pursue paths to power that actively forsake 
  their fellows. Helping others out of charity is a high crime 
  on Gehenna, but in an interesting twist the self-serving 
  nature of the plane means that alliances are actually 
  common. They simply don’t last long and nearly always 
  end in treachery and bloodshed.
  Thieves and assassins are common in Gehenna, and few 
  are as notable as the famous Sung Chiang. Most believe 
  Sung Chiang to be a god of cutthroats who built the Palace 
  of Thieves on the slopes of Khalas from bits and baubles 
  stolen from treasure chambers across the multiverse. The 
  site caters to thieves of all kind, but the masters of Sung 
  Chiang are cunning and can be found nearly anywhere.
  A few other noteworthy creatures can be found on 
  the slopes of Gehenna, including the immortal kobold 
  Gaknulak the Trickster, the serpent-eyed hag diviner 
  Laughing Jane, and the painwalkers, servants of Loviatar 
  who rules from the Frigid Fortress on Mungoth, the third 
  mount. Lost remnants of Blood War battles litter some 
  regions, and everyone who has come to live on Gehenna 
  learns to hide their most valuable possessions – which 
  means there are a great number of lost vaults scattered 
  about the volcanoes after their owners passed away.
  Lay of the Land
  The layers of Gehenna float in a limitless void of unending 
  blackness, with each layer consisting of a single enormous 
  volcano seemingly without base or top. They are each 
  hundreds of thousands of miles across but they are not 
  infinite in width – a traveler, immortal or simply possessed 
  of great speed, could move around a volcanic layer to circle 
  back to their starting point. Yugoloths and other Gehenna 
  inhabitants view this endeavor as a pointless waste of time.
  Khalas
  A savage rugged beauty holds over Khalas, the first of 
  Gehenna’s volcanic mountain layers. A crimson glow 
  suffuses the rock, evidence of the magma flowing beneath 
  the surface, but the eruptions of lava and steam are less 
  frequent here than on the more active layer, Chamada. 
  Unfortunately, it is also the layer with the most frequent 
  strikes from floating earthmotes drifting out of the void 
  to crash into the side of the volcanic slopes, sending 
  rockslides and earthquakes rumbling in great regions.
  Numerous rivers rush down the sides of Khalas, 
  swiftly crashing through gorges and canyons. The largest 
  of these channels are created by the River Styx which 
  careens down numerous waterfalls before passing into the 
  neighboring layers of the Outer Planes. The non-Styxian 
  rivers originate from further up the slopes of Khalas in 
  
  Volume XXI  |  Bleak Eternity of Gehenna
  4
  naturally occurring vortexes from the Plane of Water, and 
  they snake down the layer before evaporating from the 
  heat. Like the other layers, there is no known bottom to 
  Khalas.
  Khalas sees numerous incursions from demons and 
  devils, but yugoloths are the dominant force across the 
  volcano. Skirmishes in the Blood War are not uncommon, 
  especially since the devilish legions have always strived 
  to establish a beachhead on Khalas to move the prime 
  fighting away from Baator. These efforts are not without 
  cost, both in terms of fiendish lives and the numerous 
  contracts that have been made with the yugoloths to claim 
  part of their land.
  Chamada
  The most active of Gehenna’s volcanic layers is Chamada. 
  Rivers and geysers of lava are common occurrences and 
  the glow from the constant heat bathes the mountainside 
  in a deep crimson radiance. Many areas are as hot as the 
  Plane of Fire, so any traveler or resident of Chamada must 
  be protected from the fiery furnace burning beneath the 
  rocky surface. Soft gray ash fills the air, obscuring vision 
  beyond more than a dozen feet or so, and everywhere lava 
  flows can be found running in ever-changing channels.
  It’s difficult to believe but the Arcanaloth Conspiracy that 
  keeps yugoloth contracts is based here in the fire-shielded 
  Tower Arcane. In addition, Chamada’s intense heat is the 
  only source powerful enough to keep the Engine of Wrath 
  working – an enormous forge site run by yugoloth slaves, 
  continually pumping out weapons and armor for fiends 
  across the multiverse.
  Beneath Chamada’s surface, the lava tubes are 
  populated with magma elementals, lava sharks, magma 
  oozes, magmin, lava children, and other creatures that 
  flourish in such inhospitable conditions. Inferno wurms 
  are known to burst out of the tunnels to snatch up prey on 
  the surface at any moment, though rumors persist of an 
  ultroloth who has tamed the fearsome creatures and uses 
  them as an elite battle force.
  Mungoth
  The volcanic heat at the heart of Mungoth went cold 
  long ago, and now a deep chill settles over the rugged 
  mountainous terrain. Acidic snow falls regularly on the 
  slopes of Mungoth, and the only light on the layer comes 
  from vents of sluggish ice-cold blue lava. This natural 
  hazard is as cold as regular lava is hot through some 
  unknown powerful process churning slowly in the dying 
  volcano’s heart.
  Few creatures live on Mungoth. Loviatar, a goddess of 
  pain and suffering, holds court in her sprawling Frigid 
  Fortress, and her minions – the painstalkers – are sent out 
  on regular missions across Gehenna and the multiverse to 
  serve their dark goddess’ twisted desires. The painstalkers 
  breed powerful hunting panthers in slopes above the Frigid 
  Fortress, dangerous creatures that radiate pure pain from 
  their blue-fire ensconced bodies.
  Krangath
  A deathly silence hangs over Krangath. This volcanic 
  mountain is dead, its fire having gone out in the far distant 
  past, and now no wind or natural sound disturbs the 
  unearthly quiet that clings to the slopes like a drowning 
  victim. A dull violet radiance emanates from Krangath’s 
  core though it provides little illumination and no comfort 
  for travelers unlucky enough to have found themselves 
  traversing the Dead Furnace.
  The only activity on Krangath is found beneath the 
  surface. Shargaas the Night Lord is an orc god of stealth 
  and darkness that lives within a vast network of caves 
  known as the Night Below. The servants of Shargaas 
  include legions of orc assassins along with unnatural 
  creatures that lurk in the shadows. Exploring the Night 
  Below is a harrowing exercise in frustration, paranoia, and 
  the crushing weight of ice-cold nihilism.
  Cycle of Time
  There is no cycle of day and night on any of the mounts of 
  Gehenna. Each volcanic layer radiates its own light source 
  as well - crimson for Khalas and Chamada, icy blue for 
  Mungoth, and a deep indigo for Krangath. No moon or 
  sun hangs in the perpetual void hanging over each of the 
  layers.
  Surviving
  Each of the four mounts of Gehenna offer dangers that 
  travelers and natives must contend with, which is on top 
  of the very real threat of falling down a volcanic slope at 
  any time. The details of these problems are covered under 
  Hazards and Phenomena.
  Getting There
  There are many portals that lead directly to the Bleak 
  Eternity of Gehenna from all over the multiverse. These 
  portals usually take the form of pits or black yawning 
  chasms, and rarely do they require a key. Something about 
  the nature of Gehenna makes access into it easy, a fact 
  debated among planar scholars as a devious aspect of the 
  plane’s selfish nature.
  Portals leading out of Gehenna exist only in seemingly 
  bottomless pits placed seemingly at random on the rocky 
  slopes of all four volcanic layers. The yugoloths mark these 
  pits with their known destination in a hidden fiendish 
  script on nearby stones, but there are numerous pits that 
  are marked but are in reality simply incredibly deep holes. 
  Yugoloths find setting these traps to be an amusing past 
  time.
  The easiest way to access Gehenna is through the River 
  Styx that winds through all of the Lower Planes. The 
  wine-red river is the largest flowing river on Khalas with 
  numerous tributaries branching off from the main swift-
  moving current. Many of these branches lead to other 
  locations in the Lower Planes but it takes a skilled sailor to 
  navigate the treacherous rapids and canyons that the River 
  Styx slams through at breakneck speed.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  5
  Chamada contains numerous direct links to the Plane 
  of Magma in the Inner Planes in its fiery veins beneath 
  the volcanic surface, and it is widely believed the Dead 
  Furnace of Krangath possesses some intrinsic link to the 
  Negative Energy Plane. This would explain the presence 
  of Mellifleur the Lich-Lord’s realm of Hopelorn, where 
  arcane studies are performed at the intersection of arcane 
  necromancy and divine negative energy.
  Traveling Around
  Each of the four volcanoes of Gehenna are difficult to 
  traverse. They are rocky, steep, and dangerous to walk 
  along, and any manufactured road quickly falls into ruin 
  from the numerous rock slides and earthmotes that collide 
  into the side. Numerous caves and tunnels honeycomb 
  each of the layers, though Chamada’s are often filled with 
  swift-flowing magma.
  Traversing between each layer of Gehenna is just like 
  finding a portal out of the plane – find a bottomless pit and 
  hope that the yugoloth marks nearby tell the truth as to its 
  ultimate destination. Most native inhabitants quickly learn 
  which pits lead to other layers and other planes and which 
  ones spell doom for the unwary, but travelers should take 
  precautions when jumping into one of these seemingly 
  bottomless holes.
  The four volcanoes of Gehenna float in a never-ending 
  void of blackness that consumes light and warmth at a 
  height of about 50 feet across all layers. Beyond this height 
  creatures must possess a strong resistance to cold damage 
  but to date nothing has ever been found in the darkness, 
  though the numerous earthmotes that smash into the 
  slopes of the volcanoes must originate from somewhere. 
  It is widely believed some natural vortex to the Plane of 
  Earth exists that spits out of the earthmotes but no one has 
  found it to date.
  The Powerful and Mighty
  As befitting a plane that attracts the greedy and personally 
  motivated, Gehenna is filled with powerful creatures that 
  have lived lifetimes oppressing, killing, and stealing from 
  others to satisfy their own ambitions. Whether it’s the 
  secretive organization of arcanaloths that maintain the 
  records of yugoloth contracts, the orcish god of stealth 
  and darkness, or one of the most powerful lich-lords in 
  the multiverse, Gehenna has no shortage of dangerous 
  masterminds pulling the strings on a planar scale.
  Arcanoloth Conspiracy
  Built on a magical foundation on the fiery slope of 
  Chamada stands an iron tower decorated with blades 
  and spikes. It’s an imposing and formidable structure, but 
  there are other strongholds of grander or more sinister 
  design across Gehenna. Looks can be deceiving, and this 
  one holds a dangerous secret – it is the Tower Arcane, 
  the source of all yugoloth contracts, and it contains a 
  vast library that holds the history of the yugoloth race. It 
  is maintained by a secretive cabal known only in hushed 
  whispers as the Arcanaloth Conspiracy.
  The Arcanaloth Conspiracy is comprised solely 
  of powerful arcanaloths that have mastered arcane 
  knowledge above and beyond their fellows. They are 
  each secretive, conniving, and deceitful, but faithful in 
  their duties to the preservation of the Tower Arcane 
  and the vast stores of history and knowledge contained 
  within. The tower is much larger on the inside than 
  outward appearances would suggest, and few outside the 
  conspiracy have ever been beyond the entrance chamber to 
  explore its vast tome-laden halls.
  The Arcanaloth Conspiracy works largely to maintain 
  the records within the Tower Arcane and to progress their 
  own magical prowess. Each member has a dedicated 
  level of the tower where they work, study, and experiment, 
  attended by hosts of blind zombie slaves to perform the 
  menial work. The conspiracy was formed secretly by the 
  arcanaloths shortly after they were formed aeons ago with 
  one purpose – to find and maintain the Books of Keeping 
  that hold every true name of every yugoloth in existence 
  (plus some devil princes and demon lords). Unfortunately, 
  the four known copies of the Books of Keeping were lost 
  and now show up across the multiverse, but when they 
  hear about the Arcanaloth Conspiracy moves quickly to 
  obtain a copy at all costs.
  Gaknulak the Trickster
  Kobolds are a cowardly race, but their cowardice breeds 
  ingenuity, cunning, and a natural aptitude for traps and 
  tricks. Gaknulak was a kobold from the Material Plane 
  long ago who excelled at building insidious traps in his 
  home warrens. The traps were so cunning that his own 
  tribe fell victim to them, leaving Gaknulak alone – just 
  how the kobold wanted things. He wandered the Material 
  Plane for a period of time, moving from warren to warren 
  and teaching his skills to other kobolds, until he eventually 
  caught the eye of Kurtulmak, the kobold god.
  Kurtulmak was impressed with Gaknulak’s ingenuity 
  and challenged the brilliant trapsmith to a contest. A series 
  of caverns were chosen in the slopes of Khalas, hidden 
  away from prying eyes, and within the two formidable 
  kobold engineers built a complex network of truly 
  ingenious traps. The winner was the one to trap the most 
  travelers. Gaknulak worked tirelessly, but in the end he 
  was tricked by Kurtulmak, who built nothing and instead 
  imprisoned Gaknulak in the tunnels. But the clever kobold 
  beat his own traps and escaped, and in doing so further 
  impressed Kurtulmak. It is said that Gaknulak was made 
  immortal by the kobold god, while others say he achieved a 
  lesser godhood status.
  Regardless, Gaknulak the Trickster still wanders the 
  slopes of Khalas, alone and seemingly without a care, 
  creating elaborate tricks and traps to hamper, injure, or 
  just plain annoy travelers of all kinds. Yugoloths hate him, 
  the painstalkers of Loviatar have orders to attack him on 
  sight, and the thieves of Sung Chiang constantly seek to 
  recruit him into their order. No one has managed to bring 
  Gaknulak down to date and he seems perfectly happy with 
  a life of wandering Gehenna, making life just a little bit 
  more annoying for everyone around him.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  6
  General of Gehenna
  All yugoloth true names are recorded in the mythical 
  Books of Keeping, from the lowliest mezzoloth to the 
  greatest ultroloth and baernoloth. All, except one at least. 
  He is an immensely powerful ultroloth known only as the 
  General of Gehenna. He wanders the volcanic mountains, 
  and many lesser ultroloths have sought out the general’s 
  wisdom. Those that succeed in finding the legendary 
  warrior leave with a greater sense of the multiverse’s truths 
  and a memory gap that can never be filled regarding their 
  time spent in the general’s presence.
  The General of Gehenna often stops by the Crawling 
  City, and his appearance there is always a cause for 
  frenzied agitation and excitement. His mere presence 
  elevates lesser yugoloths to greater heights of personal 
  glory, and legends about his prowess grow year over 
  year. Whether it’s wrestling a band of solars barehanded, 
  snapping the neck of an upstart demon lord, outwitting 
  Dispater in a contest of contracts, or drinking fully from 
  the River Styx, stories about the General of Gehenna are 
  wild and varied.
  What truth is there to the general’s immense library of 
  tall tales? The Arcanaloth Conspiracy in the Tower Arcane 
  are said to hold volumes of lore surrounding the General 
  of Gehenna’s exploits but even they record little but 
  hearsay and conjecture. Ultroloths have spent their entire 
  life tracking down the General of Gehenna and have failed 
  to do so, while nycaloths have stumbled into him in bars 
  within the Crawling City. He can impart knowledge of the 
  past and future, battle wisdom earned through countless 
  campaigns, or greater truths about the nature of existence 
  itself – if only the General of Gehenna could be found.
  Laughing Jane
  The yugoloths were said to have been created by a 
  sisterhood of night hags in Hades centuries and centuries 
  ago. Whether it was at the behest of Asmodeus, Lord of 
  the Nine and ruler of Baator, or simply a desire for their 
  own fighting force, it isn’t known. Shortly after the Books 
  of Keeping were created, the night hag sisters that created 
  them fell to petty squabbling and each copy of the Books 
  of Keeping were lost. Only one of the night hag sisters 
  traveled to Gehenna with the rest of the yugoloths, and 
  now she is a mad prophet known only as Laughing Jane.
  Laughing Jane lives in the Hut of Eyes on the slopes of 
  Mungoth, surrounded at all times by thick acidic snow. 
  Black fire dances in her small hut’s hearth but Laughing 
  Jane is bothered not by the cold or acid of Mungoth’s 
  environment. She possesses divination magic unlike any of 
  her kind, but that power came with a price – her eyes have 
  been replaced with long black serpents. When she speaks, 
  she speaks through all three mouths at the same time, an 
  eerie and disquieting sound.
  Those that seek out the Hut of Eyes usually do so to 
  glean some information about the history of the planes. 
  Laughing Jane, as one of the sisters that created the 
  yugoloths, has seen much and with her serpent eyes can 
  pierce the veil of time to gaze into the past. Her words 
  are not given for free, however, and her prices are as 
  steep as they are gruesome and tend to focus on hard-to-
  find body components. She may require the tongue of a 
  lying celestial, the feathered wings of a couatl matriarch, 
  the pincers of an honest glabrezu, or any other item in 
  exchange for a glimpse into the past. By all accounts, 
  Laughing Jane’s visions are true but most are not able to 
  deliver payment to the cackling hag in the Hut of Eyes.
  Mellifleur the Lich-Lord
  Most planar scholars agree that negative energy is the 
  source of undead, or at least the primary source (some 
  sages disagree as to the extent but it is widely accepted 
  that a link to the Negative Energy Plane exists for the 
  strongest undead). Long ago, Mellifleur was a handsome, 
  respected archmage in the Material Plane, a wizard of 
  phenomenal skill and arrogance who sought to bend the 
  powers of the Negative and Positive Energy Planes to his 
  will. As death approached, Mellifleur worked diligently to 
  harness his knowledge and attain the status of lich.
  He did so, but at the moment of transformation 
  Mellifleur stumbled upon something divine. The exact 
  details are not known but most believe that Mellifleur 
  accidentally caught a divine spark meant for someone 
  else. Regardless, he became a lich and so much more, 
  and divine power coursed through his form as he became 
  Mellifleur the Lich-Lord. He worked on the Material Plane 
  for a while but found his experiments needed a more 
  appropriate platform, so he scoured the multiverse and 
  settled on Gehenna’s Dead Furnace, Krangath, which 
  seemed to possess an incredibly strong connection to the 
  Negative Energy Plane.
  Mellifleur built through arcane and divine might an 
  obsidian tower on Krangath’s void-filled slope and called 
  it Hopelorn. He attracted wizards who sought to work 
  beyond the limits of mere necromancy and tap into a 
  greater divine power to augment their spells and ability, 
  and the School of Hopelorn was born to service these 
  apprentices. Deep within the obsidian tower’s cavernous 
  depths, Mellifleur works still to blur the line between 
  arcane and divine magic through the Negative Energy 
  Plane. He remains an arrogant, self-obsessed force, 
  and his schemes have drawn attention from fiends and 
  celestials alike.
  Painstalkers of Loviatar
  Loviatar is a goddess of pain who rules a broad swath 
  of Mungoth’s frozen slope. Those cursed to live within 
  her realm are tortured constantly, and the goddess’ 
  most dedicated administrators are a band of sadists and 
  masochists known as the Painstalkers of Loviatar. Dressed 
  in black leather, their bodies drained of all blood, these 
  dangerous killers are the flayed hands and eyes of Loviatar. 
  They patrol her realm, but also range far and wide across 
  Gehenna and the multiverse on their goddess’ wishes.
  A painstalker patrol usually consists of seven members 
  and at least two painstalker panthers (specially bred 
  monstrous cats that burn with psychic blue fire). They 
  carry whips and chains and are armed with spells and 
  abilities designed to inflict pain on their victims in horrible 
  and debilitating ways. Each patrol is led by a favored 
  painstalker who reports directly to Loviatar via divine 
  
  Volume XXI  |  Bleak Eternity of Gehenna
  7
  telepathy in her Frigid Fortress, lending each patrol a 
  weight of true divine justice in their mission.
  The painstalkers themselves are believed to be vampires 
  with specific traits linking them to Loviatar’s power. This 
  includes use of pain-inducing magic and special weapons 
  designed to incapacitate victims in writhing fits of electric 
  shock. They are cruel, merciless, and utterly devoted to 
  their goddess’ mission – to bring pain and misery to every 
  corner of the multiverse.
  Shargaas the Night Lord
  The Dead Furnace of Krangath holds little on its surface, 
  but its tunnels are an intricate maze of hollow lava tubes 
  and inky darkness. The largest realm below Krangath’s 
  surface is appropriately known as the Night Below, and its 
  darkness is pure and tinged with terror. It is the home of 
  Shargaas the Night Lord, an orc god of treachery, thieves, 
  and death, and the creatures that move in this primal 
  region are utterly devoted to Shargaas’ will.
  Shargaas himself usually wanders the tunnels as a lone 
  albino orc hunter. His eyes are milky white but he senses 
  everywhere the darkness touches, so no one is hidden 
  from him in the Night Below and all are potential victims. 
  He is considered a lesser power by most standards but 
  there are no priests dedicated to his worship in Krangath. 
  The Night Below is reserved for those that honor the Night 
  Lord through their actions, and thus teams of orc and 
  half-orc assassins train relentlessly to prove their worth to 
  Shargaas.
  For his part, Shargaas doesn’t care. He lives for the thrill 
  of the hunt, and to that end he created a race of monstrous 
  creatures known as the sethalbidad (“albino stalker” in 
  the Orc language). These great insectoid monsters are 
  utterly silent and invisible except when they want to, and 
  Shargaas created them to challenge his own skills in the 
  Night Below. Some of these dangerous monsters have 
  escaped from the tunnels and now wander Kragath’s 
  slopes, making it even more perilous for unwary travelers 
  to wander the Dead Furnace for any reason.
  Thieves’ Guild of Sung Chiang
  No one really knows who runs the infamous Palace of 
  Thieves, tucked away in a canyon on a rocky slope of 
  Khalas. Its outer walls are designed in a teardrop pattern 
  to deflect boulders and other rubble that runs down 
  the slope, while within is a paradise of skullduggery, 
  profiteering, and thieving. Rogues and cutthroats from 
  across the multiverse come to the Palace of Thieves to 
  buy, sell, and trade information. A select few who prove 
  themselves a cut above their fellows receive mysterious 
  invitations to join a clandestine organization that calls 
  itself the Thieves’ Guild of Sung Chiang.
  No one really knows who Sung Chiang is. Most assume 
  he is a god of thieves that runs the palace from the 
  shadows, and it’s possible he (or she) operates in plain 
  sight using magical and mundane disguises to walk openly. 
  Those that join the Thieves’ Guild of Sung Chiang find 
  themselves receiving strange missions within the palace 
  that hint at greater treasures hidden within lost and secret 
  vaults, and occasionally they are also sent on assassination 
  or burgle missions across the multiverse.
  Who is Sung Chiang? If anyone in the thieves’ guild 
  that bears its name knows they don’t talk about it, 
  though whether it’s through fear, intimidation, magical 
  compulsion, or a lack of knowledge isn’t known. Sung 
  Chiang’s agents have struck high profile targets and 
  sites across the known planes, from a djinni citadel to a 
  guardinal lord archive to a devil prince’s pleasure palace 
  and more. They are known by their simplistic symbol – the 
  image of an eight-fingered hand in black ink.
  Creatures & Denizens
  Gehenna is a dangerous plane filled with natural hazards 
  that burn, crush, freeze, and drown. The creatures that 
  prowl the volcanic slopes are just as dangerous, from the 
  scurrying bleak rats all the way to the scheming yugoloths 
  in their strongholds and fortresses. Travelers should be 
  well-prepared to face any monsters in combat – Gehenna 
  is no place for the weak.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  8
  Avari
  Medium fiend, neutral evil
  Armor Class 16 (natural armor)
  Hit Points 38 (7d8+7)
  Speed 20 ft., fly 50 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  8 (-1)
  19 (+4)
  13 (+1)
  15 (+2)
  11 (+0)
  10 (+0)
  Skills Perception +3
  Damage Resistances lightning, force; bludgeoning, piercing, and 
  slashing from nonmagical weapons
  Damage Immunities acid, cold poison
  Condition Immunities paralyzed, poisoned
  Senses blindsight 60 ft., passive Perception 13
  Languages Abyssal, Infernal, telepathy 120 ft.
  Challenge 3 (700 XP)
  Echolocation. The avari can’t use its blindsight while deafened.
  Flyby. The avari doesn’t provoke an opportunity attack when it 
  flies out of an enemy’s reach.
  Keen Hearing. The avari has advantage on Wisdom (Perception) 
  checks that rely on hearing.
  Magic Resistance. The avari has advantage on saving throws 
  against spells and other magical effects.
  Actions
  Multiattack. The avari makes two attacks: one with its claws and 
  one with its bite.
  Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 
  Hit: 8 (1d8+4) piercing damage plus 14 (4d6) poison damage, 
  and the target must make a DC 13 Constitution saving throw or 
  be poisoned for 1 hour.
  Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 
  Hit: 11 (2d6+4) slashing damage.
  Sonic Screech (Recharge 5-6). The avari lets loose a screech 
  affecting all non-avari creatures in a 30-foot radius sphere. 
  Creatures in the radius must succeed on a DC 13 Constitution 
  saving throw or be deafened for 1 minute. Poisoned creatures 
  suffer disadvantage on this saving throw, and if they fail they 
  also suffer 14 (4d6) poison damage.
  Avari
  The avari are bat-like fiends that dwell in the dark caverns 
  that honeycomb the sides of Gehenna’s volcanic layers. 
  They are one of the few intelligent native creatures to the 
  Fourfold Furnaces, though their internal squabbling and 
  bickering has prevented them from becoming a larger 
  threat on the plane. Avari have enormous ears and a pair 
  of black leathery wings attached to their forearms. They 
  are ungainly on the ground, hopping along using their 
  small malformed legs and wing claws for support, but in 
  the air they are elegant and dangerous opponents. Their 
  skin covered in mangy fur ranging from red-brown to sickly 
  green in color.
  Eaters of Flesh. Avari crave the taste of living flesh. 
  They prefer the flesh of mortal creatures, but when they 
  can they devour the skin of yugoloths and other fiends. 
  They are adept at skinning creatures alive as a form 
  of sadistic torture, which they believe makes the meat 
  “sweeter” to their fiendish palettes. Avari have been known 
  to keep captured prisoners alive for days or weeks on end, 
  slowly removing sections of skin and flesh and letting the 
  poor tortured creature live long enough to heal to provide 
  further sustenance for the bat fiend.
  Fallen Rulers of Gehenna. Once, long ago, the avari 
  lived in delicate cities perched on the sides of Khalas and 
  Mungoth. These crystalline structures were built using 
  countless slaves, many pulled from the Material Plane, 
  who then shaped the natural rock to the whims of their 
  avari overlords. Then the yugoloths came, decimated 
  the crystal towers, and drove the avari to the dark 
  caves beneath the volcanic surface. Some cruel joke of 
  the multiverse prevented the avari from developing an 
  immunity to fire, so they must be careful in places like 
  Chamada, but they are quite well-suited to the dark slopes 
  of Mungoth. Some say the Dead Furnace of Krangath still 
  holds frozen cities of the avari but none have sought them 
  out and returned to tell the tales.
  Lords of the Caves. Avari usually keep to their 
  cavernous lairs, daring to venture out only when they know 
  they have the upper hand. They communicate with the 
  fiendish bats that share their homes and use the creatures 
  as spies and informants across the slopes of Gehenna. 
  The avari still keep scores of slaves to do their bidding, 
  but they tend to eat them on wicked whims, which means 
  they’re always looking for more slave stock. Quaggoths and 
  grimlocks are favored slaves that are easily cowed by the 
  cruel and vicious bat fiends.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  9
  Inferno Worm
  Gargantuan monstrosity, unaligned
  Armor Class 17 (natural armor)
  Hit Points 198 (12d20+72)
  Speed 40 ft., burrow 40 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  24 (+7)
  10 (+0)
  22 (+6)
  1 (-5)
  8 (-1)
  4 (-3)
  Damage Resistances bludgeoning, piercing, and slashing from 
  nonmagical weapons
  Damage Immunities fire
  Condition Immunities blinded, charmed, deafend
  Senses blindsight 60 ft., tremorsense 60 ft., passive   
  Perception 12
  Languages --
  Challenge 13 (10,000 XP)
  Fire Born. Anytime the worm is subjected to fire damage, it 
  takes no damage and instead heals the same amount up to its 
  maximum hit points.
  Tunneler. The worm can burrow through solid rock at half its 
  burrow speed and leaves a 10-foot-diameter tunnel in its wake.
  Actions
  Multiattack. The worm makes four attacks: three with its 
  tentacles and one with its tail.
  Tentacles. Melee Weapon Attack: +11 to hit, reach 15 ft., one 
  target. Hit: 16 (2d8+7) bludgeoning damage plus 7 (2d6) fire 
  damage.
  Tail. Melee Weapon Attack: +11 to hit, reach 25 ft., one target. 
  Hit: 25 (4d8+7) bludgeoning damage plus 14 (4d6) fire 
  damage, and the target is grappled (escape DC 18). The inferno 
  worm can only have on creature grappled at a time. In place of 
  a tail attack, the inferno worm can squeeze a grappled target, 
  inflicting 25 (4d8+7) bludgeoning damage plus 14 (4d6) fire 
  damage.
  Magma Spit (Recharge 5-6). The inferno worm releases a stream 
  of powerful, concentrated magma in a 10-foot wide 60-foot 
  line. Creatures caught in the area must make a DC 18 Dexterity 
  saving throw, suffering 28 (8d6) fire damage on a failed 
  save, or half as much on a success. The creature’s hit point 
  maximum is reduced by an amount equal to the damage taken. 
  This reduction lasts until the creature finishes a long rest. The 
  creature dies if this effect reduces its hit point maximum to 0.
  Inferno Worm
  Inferno worms are enormous forces of raw destructive 
  power that tunnel through Gehenna’s active volcanic 
  layers, Khalas and Chamada. They burrow close to the 
  surface, leaving a trail of honeycombed tunnels in their 
  wake that often fill up with magma or cause disruptive 
  shifts, creating earthquakes above them. The inferno 
  worm’s black hide is crisscrossed with thick veins of bright 
  red leading from its long whip-like tail to its snout, from 
  which three tentacles emerge. The creature uses these 
  radiant crimson appendages to burn through surrounding 
  rock and slap away opponents while it grabs foes with its 
  tail and squeezes the life out of them.
  Apocalypse Heralds. The arcanaloths of the Tower 
  Arcane watch the movements of inferno worms closely. 
  Some within the powerful cabal believe grand apocalyptic 
  portents can be gleaned from studying the tunnels left in 
  the wake of these great burrowing monstrosities, and they 
  have certainly built up enough evidence to suggest this is 
  more than a coincidence. Some arcanaloths have gone so 
  far as to tag the inferno worms using magical markers so 
  that they can follow the patterns on enormous maps within 
  the Tower Arcane, and they have forbidden any yugoloth 
  from harming an inferno worm for fear of disrupting the 
  pattern.
  Dead Furnace Worms. Inferno worms are instinctively 
  drawn to the magma of Gehenna’s volcanic heart, 
  especially Chamada, but some adventurers and planar 
  travelers have found evidence of inferno worm passage 
  on Mungoth and even Krangath. Are there variant worms 
  crawling through the darkness of these other layers? 
  Few reputable sources claim to have encountered such a 
  creature, but at least one scholar Hopelorn claims to have 
  seen a bone-white worm of enormous proportions on the 
  void-filled slopes of Krangath.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  10
  Painstalker Panther
  Large fiend, neutral evil
  Armor Class 14 (natural armor)
  Hit Points 67 (9d10+18)
  Speed 50 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  18 (+4)
  14 (+2)
  15 (+2)
  3 (-4)
  12 (+1)
  10 (+0)
  Skills Perception +5, Stealth +6
  Damage Resistances fire
  Damage Immunities acid, cold, psychic
  Senses darkvision 60 ft., passive Perception 15
  Languages understands Abyssal and Infernal but can’t speak
  Challenge 4 (1,100 XP)
  Keen Smell. The painstalker panther has advantage on Wisdom 
  (Perception) checks that rely on smell.
  Mark. The painstalker panther can use a bonus action to mark 
  a target it can see. The panther can only have one creature 
  marked at a time, and while the target is marked the painstalker 
  panther magically knows its location. The mark lasts for 24 
  hours unless the target dies, the panther removes it as a free 
  action, or another target is marked. The painstalker panther 
  inflicts an additional 7 (2d6) psychic damage with each attack 
  against the marked target.
  Actions
  Multiattack. The painstalker makes two attacks: one with its bite 
  and one with its claws.
  Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. 
  Hit: 9 (1d10+4) piercing damage.
  Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. 
  Hit: 11 (2d6+4) slashing damage.
  Painstalker Panther
  Painstalker panthers are bred by the servants of Loviatar, 
  goddess of pain, in hidden kennels below the Frigid 
  Fortress on Mungoth, Gehenna’s layer of acid and snow. 
  They appear as large black hunting cats with dull blue 
  streaks marking their thick fur, and their faces are 
  unusually sharp and angular. A painstalker panther can 
  mark any target it sees, a useful trait for the hunting packs 
  of Loviatar, and when the fiendish creature singles out a 
  target the panther’s body lights up with brilliant ice blue 
  flames.
  Pride of the Painstalkers. The painstalker panthers are 
  the pride and joy of the Painstalkers of Loviatar. They use 
  the magnificent hunting cats to track down prey that have 
  wronged their goddess or their order, and few are able to 
  hide from such capable packs. The panthers cannot speak 
  but understand the languages of the layer as taught by 
  their handlers, and they possess a remarkable bloodlust 
  for any creature they mark as their prey. The painstalker 
  panthers are a big reason the Painstalkers themselves are 
  feared and respected across Gehenna and even beyond the 
  Fourfold Furnaces.
  Corrupted at Birth. Painstalker panthers are trained 
  by secret kennel masters below the Frigid Fortress, but 
  they are not born as fiends. Servants of Loviatar across 
  the multiverse seek out panthers in the wild places of the 
  worlds and transport them as kittens to their mistress’ 
  Mungoth fortress. There, through profane magical rites, 
  the creatures are mutated and twisted by intense pain to 
  become painstalker panthers. The process is abominable 
  and many do not survive the transformation. Some 
  survive but become monstrosities unfit to hunt alongside 
  a Painstalker pack – these unfortunate creatures become 
  chained guardians of the Frigid Fortress, serving as 
  mindless beasts, attacking any and all they come into 
  contact with.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  11
  Sethalbidad
  Large monstrosity, neutral evil
  Armor Class 19 (leather armor)
  Hit Points 102 (12d10+36)
  Speed 50 ft., climb 50 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  21 (+5)
  15 (+2)
  17 (+3)
  3 (-4)
  10 (+0)
  1 (-5)
  Skills Perception +6, Stealth +8
  Damage Resistances fire
  Damage Immunities acid, cold, poison
  Condition Immunities blinded, charmed, poisoned
  Senses blindsight 60 ft., darkvision 120 ft., passive     
  Perception 16
  Languages understands Orc but can’t speak
  Challenge 8 (3,900 XP)
  Disappear. In dim light or darkness, the sethalbidad can use its 
  bonus action to become invisible until the end of its next turn.
  Magic Resistance. The sethalbidad has advantage on saving 
  throws against spells and other magical effects.
  Spider Climb. The sethalbidad can climb difficult surfaces, 
  including upside down on ceilings, without needing to make an 
  ability check.
  Surprise Attack. Once per turn, the sethalbidad deals an extra 
  28 (8d6) damage when it hits a target with a weapon attack and 
  has advantage on the attack roll.
  Actions
  Multiattack. The sethalbidad makes two claw attacks.
  Claw. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. 
  Hit: 17 (2d10+6) slashing damage.
  Sethalbidad
  Krangath is the lifeless, void-filled layer of Gehenna few 
  visitors travel willingly. Its slope is blanketed in a darkness 
  that seems to take on a life of its own, and the dead 
  tunnels beneath the surface are filled with nothing but 
  inky shadows. Unfortunately for the unwary, some of those 
  inky shadows are more than just imagination. In the Night 
  Below, the realm of the orc god Shargaas, monstrous 
  creatures stalk silently, seeking out new prey and fresh 
  blood. They are known as sethalbidad in the Orc language, 
  which translates roughly to “albino stalker,” and they have 
  a natural ability to disappear completely in darkness. 
  When visible, a sethalbidad appears as an enormous bone-
  white insect, with a flat head, feather-like antennae, and 
  long, thin legs. Its four back legs end in broad pads perfect 
  for moving silently in caves, while its two front arms are 
  tipped with blade-like claws.
  Chittering in the Dark. The mandibles of the 
  sethalbidad are not suitable for combat, but the orcs of 
  the Night Below have learned to listen carefully for the 
  creature’s soft noise of the mandibles clicking quietly 
  together. The caves of Shargaas’ realm have a way of 
  bending and twisting sounds, so even when a sethalbidad’s 
  telltale chittering can be heard, it can be near impossible 
  to pinpoint where the sound comes from. And by then, the 
  sethalbidad is likely already too close.
  Gift of Shargaas. Rarely, Shargaas looks upon the 
  lands beyond the Night Below to his clergy sending 
  prayers and desires. Often times the clerics are requesting 
  aid in defeating a particular foe, and if Shargaas is 
  feeling generous, he may send a sethalbidad as a gift. 
  The creature is wild and liable to attack an orc as any 
  other person, but it can be directed towards an enemy 
  encampment. Under cover of night or in the darkness of 
  tunnels, a single sethalbidad can wreak untold devastation 
  to an unprepared foe.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  12
  Slasrath
  Slasreth were originally worm-like creatures that crawled 
  through the volcanic layers of Gehenna, a source of food 
  for avari and other predators. Then, in the distant past, 
  something elevated them into ray-like flying horrors with 
  potent poison and a nasty temper. None know for sure 
  who was responsible for this transformation, though most 
  assume it was the arcanaloths of the Tower Arcane that 
  wrought the necessary sorceries. This theory is further 
  supported by the tendency of yugoloths to ride slasreths on 
  special harnesses. Wild slasreths still roam the slopes of 
  Gehenna, close to the ground, seeking out lesser creatures 
  to poison and devour.
  Razorwing Infantry of Vesh. Slasreth are sometimes 
  used as mounts by yugoloths though the winged creatures 
  are difficult to train and control, but one unit has taken 
  to the sky and made a name for themselves. Known 
  as the Razorwing Infantry, these mezzoloths ride on 
  gem-encrusted saddles strapped to their battle-scarred 
  slasreths and they are highly sought after as an elite 
  warrior force. They are led by Vesh, an ultroloth who 
  has chosen to be the best commander of the skies out of 
  any yugoloth unit. Vesh and his soldiers are based out of 
  the Crawling City but have made strikes for both devil 
  and demon forces in the Blood War all across the Lower 
  Planes.
  Slasrath
  Large beast, unaligned
  Armor Class 16 (natural armor)
  Hit Points 60 (8d10+16)
  Speed 10 ft., fly 40 ft. (hover)
  STR
  DEX
  CON
  INT
  WIS
  CHA
  15 (+2)
  20 (+5)
  14 (+2)
  3 (-4)
  11 (+0)
  7 (-2)
  Skills Perception +2
  Damage Resistances fire
  Damage Immunities poison
  Condition Immunities charmed, poisoned
  Senses darkvision 120 ft., passive Perception 12
  Languages --
  Challenge 5 (1,800 XP)
  Flyby. The slasrath doesn’t provoke an opportunity attack when 
  it flies out of an enemy’s reach.
  Actions
  Multiattack. The slasrath makes two attacks: one with its bite 
  and one with its tail stinger.
  Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 
  Hit: 9 (1d8+5) piercing damage.
  Tail Stinger. Melee Weapon Attack: +7 to hit, reach 15 ft., one 
  target. Hit: 12 (2d6+5) piercing damage plus 18 (4d8) poison 
  damage. If the target is a living creature it must succeed on a 
  DC 14 Constitution saving throw or be poisoned for 1 hour.
  Wing Slash (Recharge 5-6). The slasrath uses its large wings 
  to slash at nearby targets. Other creatures in a 20-foot sphere 
  centered on the slasrath must make a DC 14 Dexterity saving 
  throw, suffering 19 (4d6+5) slashing damage on a failure, or 
  half as much on a success.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  13
  Vaporous Horror
  Gehenna holds numerous secrets, and some frighten even 
  the yugoloths, the self-proclaimed masters of the volcanic 
  slopes. One of those mysteries are the vaporous horrors – 
  poisonous fiends comprised of toxic smoke that drain life 
  from everything they come across. A vaporous horror looks 
  like a troll made of greenish-yellow vapor with eyes of dull 
  crimson. It can slip through cracks, move on a breeze, and 
  infiltrate the most impregnable defense in search of the life 
  force it feeds on. Yugoloth, demon, devil, traveler, beast, all 
  are food to the vaporous horror.
  Unknown Origins. No one knows exactly what a 
  vaporous horror is or where they come from. They seem 
  to exist on all of the layers of Gehenna, though they are 
  rare on Mungoth and Krangath due to the lack of living 
  creatures. Some planar scholars believe they are undead 
  elementals cast off from the Inner Planes, but they seem 
  to exhibit no shared trait among other unliving monsters. 
  Vaporous horrors can speak but they rarely say anything 
  more than whispered threats and promises of pain, and 
  some block exists on a psychic level that prevents mental 
  intrusions.
  Harvesters of Flame. Vaporous horrors are thankfully 
  solitary creatures, at least most of the time. Yugoloths of 
  the Crawling City speak in hushed tones about the rare trio 
  grouping of these monstrous fiends. In these cases, they 
  elevate to become harvesters of flame, and their powers 
  and hungry are amplified to a frightening degree. To date, 
  there have only been a handful of recorded sightings 
  involving harvesters of flame, but in all cases their appetite 
  for complete destruction takes on a new form. An entire 
  legion of yugoloths were sucked up in the whirlwind of 
  death that only ended when a random earthmote crashed 
  into the trio of enhanced vaporous horrors, scattering 
  them across the volcanic slope.
  Vaporous Horror
  Large fiend, neutral evil
  Armor Class 16
  Hit Points 114 (12d10+48)
  Speed 0 ft., fly 40 ft. (hover)
  STR
  DEX
  CON
  INT
  WIS
  CHA
  5 (-3)
  22 (+6)
  19 (+4)
  11 (+0)
  12 (+1)
  8 (-1)
  Saving Throws Dex +10, Int +4
  Damage Resistances bludgeoning, lightning, piercing, slashing
  Damage Immunities acid, cold, fire, necrotic, poison, psychic
  Condition Immunities charmed, exhaustion, frightened, 
  grappled, paralyzed, petrified, poisoned, prone, restrained
  Senses darkvision 60 ft., passive Perception 11
  Languages Abyssal, Infernal
  Challenge 10 (5,900 XP)
  Magic Resistance. The vaporous horror has advantage on saving 
  throws against spells and other magical effects.
  Toxic Aura. Living creatures that start their turn within 60 feet 
  of the vaporous horror suffer 14 (4d6) poison damage.
  Vapor Form. The vaporous horror can enter a hostile creature’s 
  space and stop there. It can move through a space as narrow as 
  1 inch wide without squeezing.
  Actions
  Multiattack. The vaporous horror makes two claw attacks. It can 
  then use its Drain Life ability.
  Claw. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. 
  Hit: 11 (1d10+6) necrotic damage plus 14 (4d6) poison 
  damage. The target must succeed on a DC 16 Constitution 
  saving throw or its hit point maximum is reduced by an amount 
  equal to the necrotic damage taken. This reduction lasts until 
  the target finishes a long rest. The target dies if this effect 
  reduces its hit point maximum to 0.
  Drain Life (Recharge 5-6). Each creature in the vaporous 
  horror’s space takes 22 (4d10) necrotic damage and must 
  make a DC 16 Constitution saving throw. On a failure, a target’s 
  hit point maximum is reduced by an amount equal to the 
  necrotic damage taken. This reduction lasts until the target 
  finishes a long rest. The target dies if this effect reduces its hit 
  point maximum to 0.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  14
  Wrack Shambler
  Piles of detritus and castoff remnants of countless battles 
  and forgeries litter the sides of Gehenna’s volcanic layers, 
  the result of the yugoloth’s unquenching war machine and 
  the numerous battles fought in the Blood War. Sometimes, 
  some ambient energy of the Fourfold Furnaces slips 
  into these piles of metallic refuse, and the resultant 
  transformation creates a monstrous nightmare known 
  as a wrack shambler. These creatures are animated piles 
  of weapons, armor, and other metallic fragments that 
  exist only to destroy and tear down. They are forces of 
  nature and raw unbridled power, as much a threat to the 
  yugoloths and their war machines as anyone else, and 
  they seem only intent on unmaking as much of creation as 
  possible.
  Unmakers. Wrack shamblers are known as “unmakers” 
  to the yugoloths, and the monstrous creations of Gehenna 
  seem especially bent on destroying the works of the 
  fiends that live on the volcanic slopes. It is rumored that 
  the Crawling City that moves across Gehenna as one of 
  the strongest bastions of yugoloth power didn’t originally 
  move, but when faced with a veritable tidal wave of wrack 
  shamblers the ultroloths in charge of the city put drastic 
  plans into motion to make their fortress mobile. To this day 
  the Crawling City inherently avoids even a single wrack 
  shambler on the Gehenna slope.
  Power of Creation. To some, wrack shamblers hold 
  more than the key to unraveling magic – they possess a 
  path to ultimate creation itself. The tiefling transmuter 
  Kilthus has devoted his life to studying the properties of 
  the wrack shamblers in the hopes of harnessing an untold 
  source of creation magic latent in the Gehenna slopes. 
  Kilthus dwells with a small continent of golems and 
  assistants in the Bleak Laboratory on Khalas, where he 
  tracks down the rise of wrack shamblers and tries to force 
  them back to the lab for further study. To date they have 
  been unsuccessful.
  Wrack Shambler
  Large construct, unaligned
  Armor Class 18 (natural armor)
  Hit Points 114 (12d10+48)
  Speed 30 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  22 (+6)
  10 (+0)
  18 (+4)
  3 (-4)
  10 (+0)
  10 (+0)
  Damage Immunities acid, cold, fire, force, poison, psychic; 
  bludgeoning, piercing, and slashing from nonmagical 
  weapons
  Condition Immunities charmed, exhaustion, frightened, 
  paralyzed, petrified, poisoned
  Senses darkvision 120 ft., passive Perception 10
  Languages understands Abyssal and Infernal but can’t speak
  Challenge 8 (3,900 XP)
  Immutable Form. The wrack shambler is immune to any spell or 
  effect that would alter its form.
  Magic Resistance. The wrack shambler has advantage on saving 
  throws against spells and other magical effects.
  Magic Weapons. The wrack shambler weapon attacks are 
  magical.
  Siege Monster. The wrack shambler deals double damage to 
  objects and structures.
  Wrack Aura. Creatures affected by temporary ongoing effects 
  that start their turn within 30 feet of the wrack shambler must 
  make a DC 16 Wisdom saving throw or have the ongoing 
  effect ended for them. Only one effect or ability is removed at 
  a time, so if the creature is under multiple ongoing effects, roll 
  randomly to determine which one is removed. Ongoing effects 
  include anything that lasts a number of rounds or minutes, such 
  as a barbarian’s rage or the effects of a spell or other ability.
  Actions
  Multiattack. The wrack shambler makes two slam attacks.
  Slam. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. 
  Hit: 12 (1d12+6) slashing damage plus 22 (4d10) force 
  damage.
  Anti-Magic Burst (Recharge 5-6). The wrack shambler releases 
  a powerful burst of anti-magic energy in a 30-foot radius. Any 
  spell of 4th level or lower in the radius ends immediately.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  15
  Yugoloth
  Yugoloths have claimed Gehenna as their own. Some 
  planar scholars believe they were actually formed on the 
  Gray Waste of Hades by a powerful cabal of hags, and 
  they only later emigrated to the volcanic slopes of the 
  Fourfold Furnaces. Perhaps the move was a calculated 
  one, seeing as Hades has become a prime battleground 
  in the eternal Blood War between demon and devils, but 
  regardless of why the yugoloths are now the dominant 
  force on Gehenna. They build strongholds, towers, castles, 
  and fortifications on the dangerous slopes, ever wary for 
  the treacherous nature of the plane to send their bases 
  tumbling down, and always ready to build it all up again.
  Yugoloths are self-serving, greedy fiends that look for 
  the most advantageous angle in every circumstance. 
  They are masters at battlefield manipulation and using 
  the terrain to their advantage, and their military prowess 
  is well-regarded by fiends and celestials alike. All of this 
  doesn’t add up to a strictly coherent military hierarchy, 
  and treachery is rife among all ranks. Planar scholars are 
  relieved at this bickering and infighting, however, as the 
  yugoloths rank as one of the most dangerous fiends in 
  the Lower Planes as a whole, though they lack the iron 
  discipline of the devils or the unmatched horde of the 
  demons.
  Gacholoth
  In the arts of subterfuge, espionage, and infiltration, 
  gacholoths are without equal among their yugoloth kin. 
  These monstrous fiends are incredibly adept at deception 
  and often worm their way into enemy ranks using their 
  powerful magical abilities. There, they lay in wait for days, 
  weeks, months, or even years, waiting patiently for the 
  precise moment to make their move to complete their 
  mission in the most brutal and effective way possible.
  In its natural form, the gacholoth is a terrifying sight. It 
  stands on four legs, each muscular and ending in grasping 
  claws that allow it to climb to great heights with ease. Its 
  black skin melds perfectly in dark surroundings, and they 
  eschew weapons, preferring to use the jagged claws at the 
  end of their sinewy arms to rip foes limb from limb. They 
  move with a surprising speed and grace and are capable 
  of surprise attacks that leave opponents paralyzed with 
  pure panic. A shock of black hair runs from their bony 
  broad heads down their spines, ending in rough ebony fur 
  covering their hindquarters.
  Gacholoth
  Large fiend (yugoloth), neutral evil
  Armor Class 17 (natural armor)
  Hit Points 90 (12d10+24)
  Speed 40 ft., climb 40 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  16 (+3)
  19 (+4)
  15 (+2)
  14 (+2)
  11 (+0)
  15 (+2)
  Skills Deception +8, Intimidation +8, Perception +3,         
  Stealth +10
  Damage Resistances cold, fire, lightning; bludgeoning, piercing, 
  and slashing from nonmagical weapons
  Damage Immunities acid, poison
  Condition Immunities poisoned
  Senses blindsight 60 ft., darkvision 60 ft., passive       
  Perception 13
  Languages Abyssal, Infernal, telepathy 60 ft.
  Challenge 6 (2,300 XP)
  Alert. The gacholoth has advantage on initiative checks and 
  cannot be surprised.
  Innate Spellcasting. The gacholoth’s innate spellcasting ability 
  is Charisma (spell save DC 13). It can innately cast the following 
  spells, requiring no material components.
  At will: alter self
  3/day each: darkness, dispel magic, fear, mirror image
  Magic Resistance. The gacholoth has advantage on saving 
  throws against spells and other magical effects.
  Magic Weapons. The gacholoth’s weapon attacks are magical.
  Shock. If the gacholoth attacks a creature in the first round 
  of combat, the targeted creature must succeed on a DC 15 
  Wisdom saving throw or be paralyzed for 1 minute. Creatures 
  immune to being frightened automatically succeed on their 
  saving throw. The paralyzed target can repeat the saving throw 
  at the end of each of its turns, ending the effect on itself on a 
  successful save.
  Actions
  Multiattack. The gacholoth makes two claw attacks.
  Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 
  Hit: 11 (2d6+4) slashing damage plus 9 (2d8) acid damage.
  Teleport. The gacholoth magically teleports, along with any 
  equipment it is wearing or carrying, up to 60 feet to an 
  unoccupied space it can see.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  16
  Piscoloths
  Piscoloths are petty commanders and lead lesser 
  yugoloths in campaigns across the multiverse. They are 
  universally reviled by the mezzoloths and dergholoths, 
  and the upper leadership view them as little more than 
  conniving backstabbers looking out for their own self-
  interest above that of their units. To the piscoloths, all of 
  these views are true and they take great pride in them. 
  Their inscrutable black eyes and tentacled faces resemble 
  that of a carrion crawler, while their bodies are scarlet 
  chitin akin to a monstrous lobster. The pincers of a 
  piscoloth are razor sharp and capable of severing limbs, 
  while they walk, run, and swim using unusual avian-like 
  legs.
  Piscoloth
  Medium fiend (yugoloth), neutral evil
  Armor Class 16 (natural armor)
  Hit Points 110 (13d8+52)
  Speed 30 ft., swim 50 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  20 (+5)
  10 (+0)
  19 (+4)
  13 (+1)
  11 (+0)
  18 (+4)
  Skills Intimidation +6, Perception +3
  Damage Resistances cold, fire, lightning; bludgeoning, piercing, 
  and slashing from nonmagical weapons
  Damage Immunities acid, poison
  Condition Immunities poisoned
  Senses blindsight 60 ft., darkvision 60 ft., passive       
  Perception 13
  Languages Abyssal, Infernal, telepathy 60 ft.
  Challenge 8 (3,900 XP)
  Innate Spellcasting. The piscoloth’s innate spellcasting ability is 
  Charisma (save DC 15). It can innately cast the following spells, 
  requiring no material components.
  3/day each: darkness, dispel magic, stinking cloud
  1/day each: cloudkill, phantasmal killer
  Magic Resistance. The piscoloth has advantage on saving 
  throws against spells and other magical effects.
  Magic Weapons. The piscoloth’s weapon attacks are magical.
  Sever Limb. When the piscoloth attacks a creature with its 
  pincer and rolls a 20 on the attack roll, it severs one of the 
  creature’s limbs and inflicts an extra 27 (6d8) damage that is 
  not multiplied with a critical hit. Roll randomly to determine 
  which one (1d4: 1 left arm, 2 right arm, 3 left leg, 4 right 
  leg). Bipedal creatures missing a single leg fall prone without 
  assistance.
  Actions
  Multiattack. The piscoloth makes three attacks: two with its 
  pincers and one with its mouth tentacles.
  Mouth Tentacles. Melee Weapon Attack: +8 to hit, reach 5 ft., 
  one target. Hit: 8 (1d6+5) piercing damage, and the target must 
  make a DC 15 Constitution saving throw or be paralyzed until 
  the end of the piscoloth’s next turn.
  Pincer. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. 
  Hit: 12 (2d6+5) slashing damage.
  Teleport. The piscoloth magically teleports, along with any 
  equipment it is wearing or carrying, up to 60 feet to an 
  unoccupied space it can see.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  17
  Hazards & Phenomena
  There is a latent treachery inherent in the Bleak Eternity 
  of Gehenna that eats away positive qualities like hope, 
  compassion, and kindness. Combine that with the 
  natural hazards of four layers each comprised of a single 
  massive super volcano and the result is a dangerous, life-
  threatening plane where might makes right and the best 
  way to survive may be just to push your ally over a cliff.
  Climbing and Falling
  Very little ground movement on the surface of Gehenna 
  is done without climbing, and much of the outside is 
  considered difficult terrain due to the sloping angle 
  and piles of rocks and boulders. Every 4 hours of travel 
  requires a DC 15 Strength (Athletics) check; creatures 
  with a climb or fly speed automatically succeed. On a 
  failure, the normal distance covered is halved. If the check 
  is failed by 5 or more, the creatures takes a tumble during 
  the trip and falls. On Mungoth, the Strength (Athletics) 
  check DC is 20 due to the ice coating the slopes.
  Creatures that fall on Gehenna tumble down the slope 
  for 1d10 x 10 feet, suffering 1d6 bludgeoning damage for 
  every 20 feet. Experienced mountain climbers know to 
  use a rope, but on Khalas and Chamada, the heat from the 
  layer’s active volcano weakens non-magical rope so that it 
  snaps immediately under pressure.
  Cruel Hindrance
  The latent cruelty of Gehenna affects good deeds on an 
  intrinsic level. Whenever a creature casts a spell with a 
  beneficial effect, including a spell that restores hit points 
  or removes a condition, the caster must first make a DC 10 
  Charisma saving throw. On a failed save, the spell fails, the 
  spell slot is expended, and the action is wasted.
  In addition, anyone attempting to take the Help action 
  must succeed on a DC 10 Charisma saving throw. On a 
  failed save, the intended target of the Help action receives 
  disadvantage on their action instead of advantage.
  Furnace Vent
  The churning activity below the surface of Gehenna’s 
  layers creates noxious gases dangerous to travelers. These 
  gases occasionally burst forth in violent furnace vents, 
  spewing toxic gas in a wide area. Creatures within 50 feet 
  of a furnace vent must make a DC 15 Constitution saving 
  throw, suffering 21 (6d6) poison damage on a failed save, 
  or half as much on a success. A furnace vent lasts for 1d10 
  hours before finally exhausting and dying out. Furnace 
  vents are common occurrences on Khalas, Chamada, 
  and Mungoth, and while rare on Krangath pockets of gas 
  beneath the surface of the Dead Furnace have still been 
  known to explode out with poisonous fury.
  Krangath: Icy Void
  The Dead Furnace of Krangath is an icy wasteland devoid 
  of most life and movement. Creatures that travel its slope 
  must succeed on a DC 15 Constitution saving throw every 
  hour or gain a level of exhaustion from the cold and void-
  filled terrain. Underground, a creature must make a DC 15 
  Constitution saving throw after a long rest or gain a level 
  of exhaustion as the creeping icy void seeps into the very 
  rocks as well.
  Lava Geyser
  The active volcanoes of Khalas and Chamada can flare 
  to life with sudden ferocity, erupting in a geyser of lava 
  without a moment’s notice. A lava geyser effects an area 
  in a 20-foot diameter circle, shooting searing hot magma 
  into the air about 100 feet. Those caught in the blast must 
  make a DC 15 Dexterity saving throw, suffering 70 (20d6) 
  fire damage on failed save, or half as much on a success. 
  Regardless of the saving throw result creatures are hurled 
  away 1d6 x 10 feet from the blast. A lava geyser can last up 
  to an hour before finally settling down.
  Mungoth: Acidic Snow
  Mungoth may not be as powerfully active as the first two 
  layers, but it is just as lethal. The volcano spews ash 
  constantly in the air, and some unknown effect of the air 
  mingles with the ash to create acidic snow. Acidic snow 
  falls constantly on Mungoth’s slopes, inflicting 5 (1d10) 
  acid damage every minute. Caves and artificial structures 
  allow shelter from the constant and dangerous presence of 
  the acidic snow.
  Rockslide
  All of Gehenna’s volcanic layers are peppered by floating 
  earthmotes that collide into the slopes with tremendous 
  speed and power. When this happens a rockslide follows 
  immediately after, sending waves of rocks and debris 
  tumbling down in a great torrent of destruction. A 
  rockslide encompasses an area 1d10 x 100 feet across. 
  Creatures on the ground in the event of a rockslide must 
  make a DC 15 Constitution saving throw, suffering 35 
  (10d6) bludgeoning damage on a failed save, or half as 
  much on a success. In addition, those that fail are buried 
  beneath rubble 1d10 x 5 feet deep and begin suffocating.
  Creatures flying in the air must make a DC 15 Dexterity 
  saving throw, suffering 21 (6d6) bludgeoning damage on a 
  failed save, or half as much on a success.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  18
  Mysterious Sites & Treasures
  The greedy and treacherous are drawn to the Bleak 
  Eternity of Gehenna like flies to honey, and the self-serving 
  yugoloths have made the volcanic slopes their home 
  for centuries. One thing all of these disparate creatures 
  have in common are secrets, which makes the layers of 
  Gehenna filled with all manner of hidden caches and 
  lairs. Despite its small size, the Fourfold Furnaces holds 
  more than its share of interesting sites for adventurers to 
  uncover.
  Blood Maze of the Charred Horn
  The deep ravines and steep cliffs of Khalas hide multiple 
  secret places from prying eyes. One of these is the 
  entrance to a twisting series of caves known as the Blood 
  Maze, wherein dwell the Charred Horn tribe of degenerate 
  minotaurs. Mutated and disfigured over generations of 
  inbreeding, Charred Horn minotaurs are savage creatures 
  of bestial ferocity that hunt and kill whatever happens to 
  stumble into their befuddling lair.
  The Blood Maze itself is a wonder of minotaur 
  engineering, or at least it was at one point. It was built by 
  the patriarch of the Charred Horn tribe, Garrakar, when 
  he relocated his kin to Gehenna in an effort to establish 
  a beachhead in the name of Baphomet, the demon lord 
  of beasts. Garrakar was a brilliant strategist and an 
  accomplished wielder of arcane magic, a surprising fact 
  for one with the prowess of a great warrior, and he used 
  his skills to carve out the Blood Maze and enchant it. His 
  direct descendants still lead the Charred Horn tribe but 
  the arcane legacy of their legendary patriarch has been 
  considerably thinned.
  Yugoloths from the Crawling City occasionally conscript 
  Charred Horn minotaurs for particular savage or brutal 
  missions. The minotaurs require payment in living 
  sacrifices to populate their Blood Maze, a charge the 
  fiends are happy to provide, and rumors persist that the 
  twisting caves actually feed upon trespassers. Garrakar’s 
  tomb is supposed to lie in the heart of the Blood Maze as 
  well, guarded by ancient magic, but there are efforts within 
  the Charred Horn tribe to reclaim the glory of their great 
  ancestor.
  Books of Keeping
  The origin of the yugoloths can be traced back to a 
  sisterhood of night hags in the distant past, who used 
  mighty magic and divine power to form a race of fiends 
  that were not as chaotic as the demons or as lawful as the 
  devils. Debates rage about the guiding hand behind this 
  creation – some planar scholars say it was Asmodeus, 
  Lord of the Nine Hells, that directed the night hags, while 
  others say it was some other power. Regardless, the 
  sisterhood bound each of these newly formed fiends to 
  a series of tomes known as the Books of Keeping, which 
  recorded the true names for every yugoloth.
  True names are a powerful binding force in the 
  multiverse, and knowing the true name of a fiend or 
  celestial brings great leverage over their actions. This 
  makes having books filled with the true names of every 
  yugoloth a valuable commodity as it allows near complete 
  control over an entire race of powerful outer planar 
  denizens. There are five Books of Keeping known to exist, 
  though each contains the same raw information containing 
  yugoloth true names and each are magically updated with 
  the birth and creation of new yugoloths. However, over the 
  centuries, each copy has passed between multiple owners, 
  and many of them transcribe new true names into them 
  belonging to demon lords, devil princes, archangels, and 
  other powerful denizens of the multiverse.
  The arcanaloths of the Tower Arcane have a special 
  division devoted to tracking down and reclaiming the 
  Books of Keeping. It is widely believed they have at least 
  two copies hidden and preserved in the Tower Arcane, 
  though the secretive arcanaloths don’t speak of it outside 
  their library fortress. Beyond just a recording of true 
  names, a Book of Keeping is also said to possess the ability 
  to uncover falsehood on an almost divine level and control 
  creatures completely for a short period of time. They are 
  each potent artifacts that wreak havoc on any plane they 
  turn up on.
  Each of the Books of Keeping share a similar look. They 
  are large tomes, roughly 2 feet wide and 4 feet tall, with 
  an infinite number of pages inside. The outer binding is 
  black leather said to be formed from the skin of demons 
  and devils, and the red ink used inside is distilled from 
  the blood of angels from Mount Celestia. No writing or 
  marking exists on the exterior but the books radiate 
  powerful enchantment magic.
  Crawling City
  The Crawling City is the greatest bastion of yugoloth 
  power on Gehenna or any other plane and many view 
  it as a symbol of their place in the wider multiverse. It 
  is a massive metropolis of obsidian and ash built on an 
  enormous disk, below which sprout hundreds of giant 
  fireproof clawed legs. These legs move the entire city 
  across the layers of Gehenna, clinging to slopes and 
  providing a stabilizing force on the cliffs of the dangerous 
  volcanoes. It usually moves slowly and the legs are able to 
  transport the Crawling City over gorges and across rivers 
  of lava.
  The city itself is filled with narrow streets and towering 
  buildings housing thousands of legions of yugoloth 
  mercenaries. Lower districts hold devil and demon 
  forces as well, and despite the treacherous nature of all 
  resident fiends there exists an understood truce within 
  the Crawling City that keeps open violence to a minimum. 
  The Crawling City is commanded currently by a cunning 
  ultroloth strategist known only as the Harbinger King, 
  and it is by his whim the city moves across Gehenna’s 
  dangerous slopes.
  There are multiple factories in the city that produce fine 
  weapons and armor for use in the eternal Blood War, but 
  the pride of the Crawling City is the Academy of Eternal 
  War. Yugoloth warriors and fiendish generals teach eager 
  students tactics around the theme of war. Battlefield usage, 
  historic conflicts, command training, discipline, and more 
  are all taught at the Academy of Eternal War. Rarely are 
  non-fiends allowed into the program, but an occasional 
  mortal warlord has proven themselves to the influential 
  academy chancellor to allow admission. Few survive the 
  rigorous classes and hands-on training.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  19
  Cyst of Secrets
  Several divine powers dwell in Gehenna. One of the most 
  mysterious was Maanzecorian, the illithid god of secrets, 
  who supposedly lived in a massive lava chamber below 
  the surface of Chamada. Its presence was rumored but 
  rarely found, as befitting Maanzecorian’s divine portfolio, 
  but recent events have changed the site completely. A great 
  divine upheaval within the last century has upturned the 
  illithid god completely, exposing its realm to the greater 
  Chamada landscape, though Maanzecorian itself seems to 
  have disappeared.
  Rumors say that the demon lord Orcus was the one 
  responsible for laying low the illithid god in a bid to 
  reclaim his throne on the Abyss. Few know for sure, but 
  a great chasm now exists on Chamada that leads to the 
  remnants of Maanzecorian’s realm. It is now known as 
  the Cyst of Secrets, where strange and monstrous things 
  appear and disappear without warning. Some vestige of 
  Maanzecorian’s divine power still presides over the region, 
  and those that have gone in search of the illithid god’s 
  power report dark things writhing in the magma caves.
  Is Maanzecorian truly dead? Is there something in the 
  Cyst of Secrets that keeps a spark of the god alive? Illithids 
  don’t seem to care as none have been seen coming or 
  going from the Chamada site, but the lost home of a god of 
  secrets is bound to contain some prizes worth claiming.
  Engine of Wrath
  To support their efforts in the Blood War, the yugoloths 
  require weapons and armor on a grand scale. To this 
  end, the latent power within Chamada, the most active of 
  Gehenna’s layers, was harnessed by engineering yugoloths 
  to create a mighty factory. Referred to now as the Engine 
  of Wrath, it is an imposing iron fortress built over the 
  confluence of three lava rivers flowing like waterfalls 
  from further up the mountainside. The incoming lava is 
  channeled into titanic forges and worked by slaves of the 
  yugoloths to produce tons and tons of weapons and armor.
  Control over the Engine of Wrath has been a rotating 
  position since its creation. Currently, a bloated lazy 
  ultroloth named Maggart Shade oversees the production 
  lines, but he is interested only in lining his own pocket with 
  favors. He walks a fine line between keeping the yugoloth 
  generals well-equipped and selling fiend-forged equipment 
  to demons, devils, and even mortal warlords. This kind of 
  double-dealing is common in yugoloth society but Maggart 
  Shade must still be careful – if he becomes too brazen 
  in his working with all sides he could be usurped and 
  replaced by another. It has happened hundreds of times 
  before and it’s how he achieved his position.
  Under Maggart Shade’s predecessor, a special smelting 
  process was introduced in a special section of the Engine 
  of Wrath devoted to imbuing items with magic. Initial 
  results have been uneven but the forge masters have 
  worked in secret to refine the process while keeping their 
  powerful products out of Maggart Shade’s hands. Some 
  yugoloth legions have recently been outfitted with weapon 
  and armor imbued with magic that produces a blood rage 
  in the owner. Rumors pointing to the Engine of Wrath 
  as the source for these items are vehemently denied by 
  Maggart Shade.
  Frigid Fortress of Loviatar
  Pain and suffering rule over the realm of Loviatar on 
  the icy slope of Mungoth, a fitting fact considering her 
  portfolio is pain and suffering. The petitioners that reside 
  in the realm huddle together in small huts, constantly 
  cold and miserable, and always in fear of sudden reprisal 
  or attention from the foreboding castle at the heart of the 
  region. This is the Frigid Fortress where Loviatar and her 
  most loyal servants dwell, kept safe by black ice walls. 
  Everything within the terrifying place is devoted to the 
  art of torture, pain, and suffering, and screams constantly 
  echo from the numerous towers stretching up into the 
  bleak black sky.
  The most well-known extension of Loviatar’s will are the 
  Painstalkers. These small bands of sadists and torturers 
  enforce the will of their goddess across her realm and 
  throughout the rest of the multiverse as well. Their leather 
  garb is distinct, and they are accompanied by painstalker 
  panthers that allow them to hunt targets chosen by their 
  superiors. Caves below the Frigid Fortress hold pens 
  devoted to twisting mortal creatures into these powerful 
  hunting monsters. Above them stand multiple towers 
  where the Painstalkers themselves dwell, though they are 
  often out on assignment.
  Loviatar’s throne room sits in a massive central complex 
  referred to as the Palace of Pain. Here she hears the 
  pleadings of subjects begging for release, but she never 
  grants these desires. Instead she and her depraved court 
  relish in the wailing and begging before ultimately sending 
  petitioners down to the lower halls of the Frigid Fortress 
  for more torture before eventual release. It’s a cycle 
  without end that brings Loviatar great pleasure.
  Hopelorn
  Krangath is known as the Dead Furnace for a good 
  reason. The volcanic heart of the layer died out centuries 
  ago, and there seems to be some link between Krangath 
  and the Negative Energy Plane that exasperates the 
  icy void. Almost nothing disturbs the exterior slopes 
  beneath the blackened canopy of eternal night. Krangath 
  is inhospitable to life – a fact that caught the attention of 
  Mellifleur the Lich-Lord. Mellifleur’s checkered history 
  placed him as a lich with the power of a god by accident, 
  and he wandered the multiverse for a period of time 
  looking for something.
  He found it on Krangath, a perfect confluence of planar 
  power and expanding negative energy that he could exert 
  his divine prowess . He established a tower to study the 
  energy of the Dead Furnace in the hopes of harnessing 
  it for his own personal use and learning more about the 
  intersection between divine and arcane magic. Soon, his 
  divine status attracted a small following, and so Mellifleur 
  the Lich-Lord worked with the eager necromancers and 
  death priests to establish Hopelorn.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  20
  The tower of Mellifleur is now surrounded by smaller 
  buildings that house students and priests that wish to learn 
  more about the necromantic power inherent in divine and 
  arcane magic. The Lich-Lord rarely makes his presence 
  known outside of his personal chambers and the leaders 
  of Hopelorn do not rely on their aloof demigod to provide 
  guidance. The research and work being done on the 
  slopes of Krangath appeal to a great number of aspiring 
  necromancers, some even devoted to using their power 
  to better understand life and help others, though most 
  are conniving masters of deception looking to increase 
  their power by taking advantage of Mellifleur’s extensive 
  resources.
  Hut of Eyes
  Prophecy and secrets are the currency in the home of 
  Laughing Jane, a reclusive and ancient night hag who lives 
  in a secluded valley on the icy slopes of Mungoth. The 
  valley is filled with black rock formations that resemble 
  twisted trees, all covered in heavy layers of acidic snow, 
  and in the center sits the simple and unassuming home of 
  Laughing Jane, the Hut of Eyes. The night hag’s eyes have 
  been replaced by serpents, and when she speaks she does 
  so using all three mouths in an unnerving fashion.
  Laughing Jane is one of the oldest night hags in the 
  multiverse. It is rumored she was part of the sisterhood 
  that created the yugoloths and the Books of Keeping, and 
  if true she has witnessed much of the formation of the 
  planes. She is truly insane however – whatever power 
  Laughing Jane traded for her eyes infected her mind as 
  well. Now, she huddles in the Hut of Eyes alone, laughing 
  maniacally to herself in the light of a blackfire hearth as 
  acidic snow falls forever in the valley.
  Enough stories have been shared regarding Laughing 
  Jane’s prophetic visions and incredible lifespan to bring 
  travelers from across the planes seeking out her abode. 
  She cackles and chuckles constantly, but between her 
  ramblings she requests payment in exchange for the 
  divination knowledge she holds. The payment is usually 
  in the form of a body part from some hard to find source 
  – the fingernail of a demon lord, a lock of hair from an 
  archangel, the eye of a sightless froghemoth, that kind of 
  thing. Those that return with the requisite payment earn a 
  glimpse into the past, present, or future that few can rival.
  Lost Warrens of Gaknulak
  There are few more revered figures in kobold history than 
  mischievous Gaknulak. He was a kobold from the Material 
  Plane who built ingenious traps from the whimsical to the 
  downright lethal, and he won the attention of Kurtulmak, 
  the god of kobolds, with his brilliant trapsmithing skills. 
  Kurtulmak challenged Gaknulak to a contest to see who 
  could build the ultimate trap-filled warren. A series of 
  caves on Khalas, the first volcanic mount of Gehenna, was 
  chosen, and Gaknulak immediately set to devising traps 
  that outdid anything he had crafted previously.
  Ultimately, though, Kurtulmak tricked Gaknulak and 
  planned on imprisoning the arrogant mortal kobold in the 
  trap-filled warren. But Gaknulak was able to defeat his 
  own creations, and in honor of the great feat Kurtulmak 
  granted the kobold trapsmith immortal status. The 
  caves filled with Gaknulak’s insidious, dangerous, and 
  sometimes wacky traps still lay on Khalas, now known as 
  the Lost Warrens. Gaknulak still drops off treasures within 
  the recesses of the Lost Warrens, and it is said Kurtulmak 
  even hides a few precious items within the tunnels.
  Night Below
  The Dead Furnace of Krangath may be quiet and nearly 
  undisturbed on the surface, but below the cold stones 
  sprawls a labyrinth of darkness-filled tunnels. The most 
  expansive collection of these are known as the Night 
  Below and they form the realm of Shargaas the Night 
  Lord, orc god of stealth and shadows. Special properties 
  embedded within the stones of the Night Below inhibits 
  light of all kinds, dimming it to be nearly worthless – and 
  for those foolish enough to need light, a swift death awaits 
  from the orc hunters and other monsters that patrol the 
  tunnels.
  Shargaas keeps a personal sanctuary in the heart of the 
  Night Below. It is surrounded by life-draining patches of 
  pure negative energy that move like wraiths, but beyond 
  sits the treasure trove of a greedy orc god known for 
  stealing what he wants whenever he wants it. Blind albino 
  orc assassins blessed by the Night Lord protect their great 
  god’s treasure chamber but are forbidden from touching 
  any of it.
  The most insidious monster to stalk the Night Below 
  are the sethalbidad. These insectoid monsters blend into 
  patches of darkness with ease and stalk silently anyone 
  who dares to intrude upon Shargaas’ night-filled realm.
  It is said that the Night Below contains pools of pure 
  distilled darkness that can be captured in liquid form by 
  the brave or foolish. This concentrated darkness can be 
  utilized as an enhanced component for spells such as 
  darkness to create powerful effects. Retrieving such liquid 
  darkness requires facing the minions of Shargaas, and 
  perhaps the Night Lord himself, who is rumored to be able 
  to see out of these pools of darkness.
  Nimicri
  In a remote section of Chamada, floating above the 
  volcanic surface hangs a strange sight. It appears to be a 
  fog-enshrouded town on an earthmote that never touches 
  the ground, hanging about 50 feet in the air. Its streets are 
  eerily quiet and the buildings seem deserted, but anyone 
  who travels there meet strange people that welcome 
  travelers with open hospitality. Few escape with their lives 
  after walking the streets of Nimicri, as nothing is at is 
  seems.
  For starters, Nimicri is not a town. It’s an enormous 
  living mimic that has chosen the form of a town to lure 
  in victims to devour. Any person met in the streets or 
  buildings of Nimicri is likely an extension of the powerful 
  mimic, creating people out of its own mass to lure 
  victims into a false sense of security. Sharp-eyed visitors 
  
  Volume XXI  |  Bleak Eternity of Gehenna
  21
  may notice that these “people” never lose at least some 
  connection to the ground
  Nimicri has devoured enough people that it has 
  accumulated a fair bit of treasure. It’s intelligent enough to 
  use the shiny coins, gems, and magical items as a further 
  lure, as its getting harder and harder to fool creatures into 
  stepping onto its streets willingly. For those that do fall for 
  the trap, a messy fate awaits.
  Palace of Thieves
  Thieves are a natural fit for Gehenna’s self-serving and 
  treacherous nature. Nowhere is this better exemplified 
  than the fabulous Palace of Thieves, a grand complex built 
  on a permanently stable slab on Khalas’ steep slope. The 
  teardrop shape of the surrounding high walls allows for 
  rockslides from further up break apart without tearing into 
  the main buildings, though many suspect magic plays a 
  hand at keeping the Palace of Thieves safe and secure as 
  well.
  Inside is one of the greatest gathering of thieves, 
  cutthroats, knaves, and ne’er-do-wells in all of Gehenna. 
  Rogues from across the multiverse come to the Palace 
  of Thieves to prove themselves to their fellows, to find 
  jobs, to swap stories, and to fence stolen goods. A few 
  shady merchants have setup permanent shops within the 
  palace grounds, catering their services to the surrounding 
  clientele. Those with scruples are ferreted out immediately.
  Over it all watches the mysterious Thieves’ Guild of 
  Sung Chiang. Though no one official runs the Palace of 
  Thieves, this one band maintains the peace and keeps the 
  palace from collapsing in on itself in a treacherous tumble 
  of deceit and murder. Some have claimed to have seen the 
  perpetually absent Sung Chiang and claim he is a monkey-
  fiend with eight arms, but many more believe him to be 
  merely a myth, a name passed down to keep the mystique 
  of the Palace of Thieves alive.
  Perhaps Sung Chiang is real, and perhaps not. But 
  what is very real are the hundreds of hidden treasure 
  caches scattered about the palace. By ancient decree 
  the cutthroats that came to the Palace of Thieves are 
  forbidden from seeking out others’ treasure, a decree 
  enforced by dangerous members of the Thieves’ Guild of 
  Sung Chiang. There are loopholes to this decree, however, 
  and many rogues have tried to bring in outsiders as hired 
  muscle to dig up treasure outside the rule of Sung Chiang’s 
  forces.
  Tower Arcane
  The Crawling City may be the greatest stronghold of 
  yugoloth construction, but the Tower Arcane holds its most 
  potent secrets and stands as the center of their magical 
  might. Located on the volcanic slope of Chamada in the 
  midst of a raging lake of lava, the Tower Arcane is run by 
  the Arcanaloth Conspiracy. These fiends are obsessed with 
  obtaining knowledge of all kind and secreting it away in 
  the tower’s many library halls.
  The Tower Arcane is a squat tower made of obsidian that 
  stands barely 100 feet tall. It has no windows and only a 
  single door, with a crumbling stone staircase leading to the 
  great ruby doors. Inside, however, is an expanding space 
  not unlike a bag of holding. Great halls filled with books 
  devoted to all manner of subjects lay locked away within 
  the Tower Arcane, kept and guarded by the arcanaloths. 
  Any yugoloth can request information from the Tower 
  Arcane but bribery is required, and the arcanaloths who 
  run it seek only magical treasures as payment.
  Beyond the recorded history of the yugoloths, the 
  Tower Arcane is said to hold a copy of every arcane spell 
  in the multiverse. New spells are added to the expansive 
  catalogue on a regular basis, and the arcanaloths are more 
  willing to work with outsiders to achieve their goals than 
  other fiends. Only the foolish enter into such arrangements 
  without precautions however – the treacherous 
  arcanaloths are just as self-serving as their more common 
  brethren.
  Vast swaths of the Tower Arcane are devoted to 
  contracts as well. A copy of every contract a yugoloth 
  makes is magically created within the record halls of the 
  Tower Arcane. The record-keeping of the arcanaloths in 
  the Tower Arcane is legendary, and they’ve been called 
  upon by the Lex of Arcadia as witnesses and evidence 
  providers on numerous occasions. An uneasy alliance 
  exists between the courts of Lex and the arcanaloths of 
  the Tower Arcane, though both recognize the value of the 
  other in a broader sense.
  Valley of the Outcast
  There are few sanctuaries in the acid-snow filled slopes of 
  Mungoth. Even escaping into the tunnels is a dangerous 
  proposition filled with peril. One of the few respites 
  available to lost travelers is the Valley of the Outcast, 
  magically protected from the acid snow by arcane might, 
  though the hosts of the enormous castle in the center of 
  the valley are not the friendliest. The fire giants of the 
  Scorchscar family, led by their matriarch Tastuo, were 
  exiled from the Plane of Fire long ago and have managed 
  to make a life for themselves on Mungoth.
  Tastuo and her sisters are all accomplished wizards who 
  were forced out of the court of Surtur, god of fire giants, 
  for some slight long ago. By divine ordnance they couldn’t 
  rest in any place that was not cold, so they found the frozen 
  landscape of Mungoth and decided to make the best of 
  it. They hunt wild beasts in their valley brought in via 
  magic not native to Gehenna, but their magic prevents the 
  acid snow from harming them or their home. Tastuo has 
  several contracts with yugoloths to act as an intermediary 
  as well, so she in on relatively good terms with the local 
  fiends.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  22
  Adventure Hooks
  Everything about the nature of Gehenna wears down on 
  good and helpful folk. Adventurers tend to fall into this 
  category for the most part, but there are still elements to 
  the volcanic slopes that can draw heroes from all across 
  the multiverse, whether it’s stopping warlords, liberating 
  treasure, or uncovering some planar secret.
  Tier 1 (levels 1-4)
  There are plenty of ways to involve tier 1 characters in the 
  machinations of Gehenna and its selfish residents. Not 
  all of them involve a trip to the volcanic slopes, especially 
  Mungoth and Krangath which can pose real problems for 
  characters of this tier.
  … A desperate man runs to the characters for help. He 
  claim to be pursued by a band of leather-clad, whip-
  wielding thugs with some dangerous looking panthers. 
  The man is being pursued by a band of Painstalkers of 
  Loviatar, who believe the man to be an escaped petitioner 
  from the Frigid Fortress on Mungoth. This isn’t true, so the 
  characters must convince the Painstalkers of the mistake, 
  and then they can help track down the real fugitive. Do the 
  characters release the pitiful escapee into the hands of the 
  Painstalkers? Or do they defy the will of a goddess?
  … Something is killing the members of a small town on the 
  outskirts of civilization. The culprit is a pair of barghests 
  leading a tribe of goblins to devour souls, but they have 
  a larger mission as well – to uncover a lost weapon of 
  war believed to be buried under the town’s temple. The 
  barghests and goblins have chosen to isolate the town and 
  pick them off one by one, mainly because they are cruel 
  and vicious, but they are not counting on outside help. Can 
  the characters defeat the menace? And is there a weapon 
  of war used by ancient yugoloths buried under the temple?
  … A necromancer of Hopelorn has gone out in search of 
  test subjects for necromantic experiments. They’ve setup a 
  lair in the sewers below a major city and have broken into 
  a series of forgotten crypts, pillaging the corpses for use as 
  experimental undead. The resultant zombies and skeletons 
  are built from divine and arcane magic, making them 
  immune to turning, and granting them the use of limited 
  arcane magic. The monsters are sent out to cause as much 
  mayhem as possible so the characters can get drawn in by 
  rising up to stop the tide of unusual undead. The trail leads 
  to the necromancer’s lair but they escape to Hopelorn. Do 
  the characters follow to administer justice? Or do they bide 
  their time until they can learn more about the Lich-Lord’s 
  void-filled home?
  Tier 2 (levels 5-10)
  Characters that advance to tier 2 are able to better 
  withstand and explore the dangers of Gehenna, and they 
  can easily find themselves embroiled in the far-reaching 
  plots of yugoloths and other greedy denizens.
  … A hapless rogue comes to the characters asking for 
  their help in recovering a lost treasure hidden away in the 
  Palace of Thieves. He claims to be good with the Thieves’ 
  Guild of Sung Chiang and he produces a map of the 
  treasure’s location. The ancient decree prevents him or 
  other thieves from getting it so that’s why he needs outside 
  help. Is the rogue on the up and up? Or is there a betrayal 
  in the Palace of Thieves waiting for the characters?
  … The trail of a missing family leads the characters to a 
  cave with a portal leading to Gehenna, specifically the 
  ruined underground city of the avari. The family are 
  enslaved by the bat fiends along with countless others 
  in a massive operation to restore the city to its former 
  glory, unless the characters can strike a blow against the 
  monstrous avari and their ghoulish appetites. But what 
  greater evil lurks within the temple built out of a single 
  stalactite in the cavern’s center?
  … In an alley at night the characters witness a horrendous 
  sight – a near invisible sethalbidad strikes down a pair of 
  drunken thugs. Do the characters intervene to save the 
  thugs? The problems grow worse as slayings continue in 
  the town, which turns out to the be work of an orc cleric of 
  Shargaas and a band of assassins who were cheated out of 
  a contract by a rival guild. They called upon the Night Lord 
  to deliver vengeance and the distant deity delivered – but 
  now there are too many sethalbidad and everything’s gone 
  pear-shaped for the orcs.
  Tiers 3 and 4 (levels 11+)
  As their abilities expand, characters of the higher tiers 
  usually begin seeking greater and greater dangers to 
  thwart and challenges to meet. Gehenna has plenty of 
  both!
  … A mighty general comes to the party seeking their aid. 
  In a desperate hour of need the general sold her soul to 
  a yugoloth, but in the end her soldiers were victorious 
  without the need of the fiend’s assistance. Unfortunately, 
  the contract remains and now the yugoloth has come 
  to collect. The general asks the characters to go to the 
  Crawling City to meet with the yugoloth who holds her 
  contract. Finding the obsidian city on the slopes of Khalas 
  is part of the problem, while navigating the narrow streets 
  is another. Are the characters able to convince the yugoloth 
  to renege on the deal?
  … A horrendous problem vexes the party, and one of the 
  only avenues to solving it lies with Laughing Jane in the 
  Hut of Eyes. The cackling night hag in the Mungoth valley 
  demands a strange payment for her information – the 
  tears of a blind demon. Finding such a fiend sends the 
  party around the Lower Planes. Is it a wild goose chase? 
  Laughing Jane’s reputation is always to deliver but her 
  words can often be as cryptic as they are helpful.
  
  Volume XXI  |  Bleak Eternity of Gehenna
  23
  Random Encounter Tables
  The below tables can be used by the Dungeon Master 
  as a source of inspiration when a party of characters 
  are traveling through Gehenna. Though each layer has 
  its own unique flora and fauna, the table below can be 
  used on almost any of the layers to throw challenges at a 
  band of characters. Two tables are provided, one for the 
  surface encounters and another for underground. Look 
  at each one as a springboard for new adventure ideas, or 
  as a means of highlighting the nature of the plane for the 
  players.
  Gehenna Surface
  1d100
  Gehenna Surface
  01-05
  A flying formation of slasrath
  06-10
  A lone mezzoloth separated from its unit
  11-15
  A wrack shambler rising from a pile of 
  debris
  16-20
  A night hag in a carriage being pulled by 
  minotaurs
  21-25
  An assassin looking for the Palace of 
  Thieves
  26-30
  An oinoloth picking through the remnants 
  of a battle
  31-35
  Two nycaloths flying through the air
  36-40
  A vaporous horror sensing nearby life to 
  drain
  41-45
  The ghost of a defeated wizard bound to the 
  rocks where he died
  46-50
  A hydroloth enjoying basking on a rock
  51-55
  An arcanaloth accompanied by a group of 
  mezzoloths cataloguing events
  56-60
  Mercenary knights of a local warlord 
  patrolling their border
  61-65
  A group of giants looking to rumble (stone 
  giants on Khalas, fire giants on Chamada, 
  frost giants on Mungoth)
  66-70
  A succubus on the prowl for a new target
  71-75
  A piscoloth commander ordering 
  mezzoloth troops in drills
  76-80
  A band of barghests hunting on the slopes
  81-85
  An inferno worm sensing movement on the 
  surface
  86-90
  Lava geyser
  91-95
  Furnace vent
  96-00
  Rockslide
  Gehenna Underground
  1d100
  Gehenna underGround
  01-10
  Several swarm of bats scattering from the 
  sudden movement
  11-20
  A band of avari hunting in the dark
  21-30
  A unit of mezzoloths searching for a 
  deserter
  31-40
  Hungry ghouls protecting their charnel pit
  41-50
  Bestial minotaurs gone savage and insane
  51-60
  An enormous fiendish carrion crawler
  61-70
  A sethalibidad on the prowl for fresh meat
  71-80
  Furnace vent
  81-90
  Lava geyser
  91-00
  An inferno worm bursting from the ground
  
SOURCE: textdata/thevault/Dungeons & Dragons [multi]/5th Edition (5e)/3rd Party/Dave Coulson/Codex of the Infinite Planes - Vol 21 - Gehenna.pdf