Have you seen him yet? If you have, did he spawn in Grenth's or in the Furnace? IF he spawned in the Furnace, do you remember where or which quest you were doing?
He was in furnace when i found him...i went in with NO quests and he was in the room after the first one (through the back gate) i have seen him there a few times...but the boss locations are random
I know the boss location is random, but the EA doesn't seem to be. (ex. Yakslapper is in Grenth's, not Furnace.) But if you've seen him in that 2nd room, I can zone til he spawns there.