Horcos Karun is the curent lord of the Abyss. His infinite forces constantly fight to overtake the material plane, but are held back by a blood union of devils angels and mortals. This eternal war is known as the Blood War.
Horcos Karun cares for nothing save himself - not even his devotees and undead servants - and focuses only on spreading misery and evil. He can sustain a mortal form while possessing a humanoid corpse and is known for directing mortal servants from this pseudo-avatar form.