Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - Technical Issues Can't kill Pontius

I had that glitch few times even if not in this specific fight.

I had to take control of the character that was glitched walking around outside combat even though in combat range, one that could not interact or talk to NPC's...I took control of that character and forced him to attack things himself and specifically have him initiate combat while the other characters held back out of combat range, it seemed to correct itself after while doing that.

Also doing things like if he or she could not initiate dialogue I would have another character initiate the chat with NPC and then just switch to the non functioning character and sell some stuff to the NPC from that character. Stuff like that fixed it for me. Could also try making your other companions hit that character or kill and resurrect him/her I guess.