the Desians have reemerged and are terrorizing humanity, conducting biological experiments on abducted humans in facilities known as "human ranches", which further consumes mana. During this time, humanity puts his hopes upon the descendant of Martel's angels, the "Chosen", who must undertake a pilgrimage and awaken the "Summon Spirits" who protect Sylverant. This will in turn awaken Martel, who will reseal the Desians and restore the world's mana, and the Chosen will be reborn as an angel. The Chosen's pilgrimage is complicated by the presence of the Renegades, a group that deliberately dresses in Desian garb and has assassinated Sylverant's Chosen for the past 800 years, preventing Martel's awakening. Later, the existence of a parallel world named Tethe'alla comes to light. The two worlds are separated by a dimensional barrier that can only be passed through using magical technology (or "magitech"). They share a single source of mana and are caught in a precarious equilibrium in which mana is unevenly distributed; as one world prospers, the other declines. Sylverant and Tethe'alla are inhabited by humans as well as elves, a race of long-lived humanoid extraterrestrials who originated from the giant comet Derris-Kharlan and can manipulate mana to cast magic. Offspring born between humans and elves are half-elves, who bear both the fighting spirit and curiosity of humans and the longevity and magical capabilities of elves. Because of this, they are discriminated against by condescending elves and jealous humans, and in Tethe'alla they are deprived of civil rights. The Desians are composed entirely of half-elves who act out of vengeance for this discrimination. Several characters bear an "Exsphere", a small jewel that enhances the wearer's natural abilities when implanted onto the skin, and is also used as a power source for machinery. However, an Exsphere's amplifying capability can only be awakened at the cost of a human life, and the Exsphere parasitically feeds off the user's mana unless a suppressant named a "Key Crest" is installed. An evolved form of Exsphere known as a "Cruxis Crystal" grants its user immortality, a pair of angel-like wings, and a relinquished need for human functions such as eating or sleeping, but eventually erases the user's ego if worn without a Key Crest. The Chosen is said to be born holding a Cruxis Crystal, though it is actually granted by its namesake organization Cruxis, the central body of the religion surrounding Martel. Cruxis' duty is