If he didn't cast timestop then it definately is *not* the demogorgon as he was originally supposed to be until he was weakened for balance purposes (to say you can reach him at chapter 2 in SoA). The original demogorgon was not really a challenge for me, but the tougher version is damn hard. Demons are *constantly* summoned and the guy has close on 400HP which is a damn load more than he had. He also continually casts stoneskin everytime you get through to him so you need to breach breach breach. It certainly is no easy affair. I've done the improved Abazigal which still wasn't too hard (finished the lot off with no casualties on the second attempt). I had the most fun with Balthazar as they made him obscenely powerful, and just before you kill him, he regains all his HP and returns to uninjured once again, so you need to assault hard for a second time. The hardest modified battle IMO is Yaga Sura. Damn this was hard. They've given him 99% resistances to all forms of damage (slashing, crushing etc) and also something daft like 400HP so even with 4 fighters using greater wirlwind it takes *ages* to drop him!!
Oh, and watchers keep is the best dungeon in SoA + ToB. I never get bored of doing this. It's been very well planned and deserves maximum credit. Almost all enemies you can think of are encountered here (including dragons, demi-liches, hive mothers etc) and the tresures are absolutely cool
