The Abyss is a dangerous, Shadowy Realm described as a graveyard for Worlds. Worlds that are scourged of life and are unanchored disappear into the primordial darkness of the Abyss.
There are many large and monstrous beings that originate in the Abyss. The armies of the Second Kingdom and others sometimes employ such creatures in their forces.
During the course of Darksiders 2 it was revealed that War's Soul resided in the Abyss during the century that he was imprisoned and that the Chosen originated from this Realm.