Uh...
Given that I just played (and finished, gleeeeeeee) ADOM, I guess that'd be the forces of chaos. Fistanarius the greater Balor, the various orb guardians, Andor Drakon the elder chaos god... could be working for any one of those, I suppose.
Good news: The hero will likely die before getting to me.
Bad news: If I don't have the luck of being, say, a goblin and end up being a chaos (insert noun here), I'm in big trouble. Because, you know, corrupted/mutated/insane/generally quite far gone. Also if I die the "hero" will probably eat, reanimate or sacrifice my corpse. Yaaaay.