The Abyss

The Abyss is one of the Dark Realms and is the home realm of demonkind. It was once ruled by Orcus the Demonking, but is now the dominion of Asmodeus following his victory in the Blood War. Orcus now dwells in an eternal prison of Asmodeus' making, and the abyssal demons now serve as thralls for Asmodeus' interplanar invasions.