Okay, well first, as you have probably discovered, Aec will respawn if you kill him before the cultists are killed. So you have to kill the cultists first.
1) Buy the 4 potions of mirrored eyes at the inn and give them to your front line fighters.
2) Potion up and cast all defensive spells. Among these I included Free Action and Resist Fear. Have Remove Fear prepared. See 6 below; make one character invisible.
3) After appearing downstairs pause immediately (right before dialogue).
4) Target a couple of gangs of monsters to appear around Aec with wand.
5) Target the cult leader who is standing right in front of you and kill her quickly (she's not that hard to kill).
From this point onward there are several ways but this is the one I liked the best:
6) With either a stealthed thief or invisibilized character wearing the cloak of Algernon walk around the room and charm each of the cultists and direct them to attack Aec.
7) Aec will ignore your party as he fights the summoned monsters and the cultists. When all of the cultists are killed then begin your attack on him. Honestly, I can't remember exactly how I took him down, but he is much easier to kill when all of the cultists are dead. Just keep laying monsters and skellies on him to keep him busy. He has magic resistance but he does eventually go down from magic arrows and wands (IIRC, especially the Wand of Heavens).
[This message has been edited by Lemernis (edited 09-03-2001).]
[This message has been edited by Lemernis (edited 09-03-2001).]