[Kaleban]

Solution: Buy two things - Shield of Balduran and a Protection from Undead scroll.

Put on the Shield, and after Shangalar does his dialogue, read the PfU scroll on yourself. You'll be out of the line of sight of the Time-Stop magess, the beholder will kill itself on your shield, shangalar and the vampire won't see you, so all you have to worry about initially is the thief. Kill him, heal, then pound on Shangalar (the Beholder should have deathed/stoned/charmed/etc/etc itself by now) and his Mislead. Kill him, then go after the wizardess. Once you've downed her (you could buy a Protection from Magic scroll and cast it on her if you're a low level), proceed to chop up the vampire.

Grab the eye and Staff of the Magi, and you're home free.