I can't kill Grushnak

[Orion]

Periodically he seems to activate some kind of ability that causes my attacks to heal him instead of hurting him. He has no listed damage affinities, no buff appears on his effect list, and none of his listed talents should do this. I have no way of telling whether it is on or off.

[breadsmith]

If I remember correctly. he has a heal upon dealing damage ability, and I'm pretty sure he has a high level of Vitality, thus getting a huge boost to regen when he's weak enough.