I've had a bug where Keara instakills me from 740 health and 30% MR if I piss off Velanir to get him to join in the fight. I was Level 33, wearing the Complete Scorpion Set.
That one seems like a Magic Blast or two, and Geishnz instakills me with what I think is a polymorph + Magic Blast combination at 749 health and 30% MR. Level 33 Scorpion set as well. I didn't even have time to retreat after the conversation ended.