wave with increased enemy spawn that they must survive before they can escape. Collectible intels are also scattered around the playable maps, allowing players to keep track of and unfold the main story as they progress. A skill upgrade system is featured in the game, allowing players to enhance weapons, perks, ammo mods and field upgrades with Aetherium Crystals, a currency acquired from reaching round milestones. A new game mode, Onslaught, was introduced exclusively to PlayStation players until November 1, 2021. In this mode, which are played within Multiplayer maps, up to 2 players defend areas grounded off by the Dark Aether orb, which must be powered by zombie kills. Sufficient kills will move the orb to new positions, forcing the players to move or die outside of the orb's protection zone. The Season Two update introduces "Outbreak", a large-scale mode where players fight off zombie hordes and complete objectives in an open-world area, composed of locations featured in the larger Multiplayer modes. Plot Characters and settings Call of Duty: Black Ops Cold War is set during the Cold War in the early 1980s. The campaign follows Green Beret turned CIA SAD/SOG officer Russell Adler (Bruce Thomas) and his mission to stop an international espionage threat named Perseus (William Salyers) in 1981. The story is inspired by actual events and the campaign features locations such as East Berlin, Vietnam, Turkey, and the Soviet KGB headquarters. Adler is supported by returning Black Ops characters Alex Mason (Chris Payne Gilbert), Frank Woods (Damon Victor Allen) and Jason Hudson (Piotr Michael), alongside fellow MACV-SOG operative Lawrence Sims (Reggie Watkins), Mossad fixer Eleazar "Lazar" Azoulay (Damon Dayoub), and MI6 intelligence officer Helen Park (Lily Cowles), with additional support from KGB Head of Security and undercover agent Dimitri Belikov (Mark Ivanir). Players take on the role of "Bell", a mysterious operative who assists Adler and his team in finding Perseus for the majority of the campaign; Mason and Belikov are also playable in certain segments. Perseus' inner circle consists of: Iranian terrorists Arash Kadivar (Navid Negahban) and Qasim Javadi (Farshad Farahat), Russian mafia boss Anton Volkov (Rafael Petardi), rogue KGB Agent Major Vadim Rudnik and ex-CIA officer Robert Aldrich. The campaign also features a brief appearance by Imran Zakhaev (Dan Donohue), father of Call of Duty: Modern Warfare antagonist Victor Zakhaev, and Colonel Lev Kravchenko (Andrew Divoff), a former nemesis of Mason and Woods whom