ah yes, thanks. i finally found a way around the stunning. they give you enough turns before the fight to summon, haste wand, and battle crystal. then since the demon won't move, i kept my player just two spaces away so he could only attack me from afar, (you have to be right next to him for him to stun you). then i made sure i used lightning and arcane blow enough so he and his little demons always attacked me and not my summons. that left just enough attack rounds for the three of us to kill him off. using the "kill" wand with battle discipline mighty blow really helped. i have about 35% fatigue removal so i could use that often enough.
i'm pretty sure i couldn't do this at a more difficult level though...