My strategy for a boss
I was having a hard time with the battle against Balthazar. So on my 4th attempt, I entered conversation with him, switched to Karlach, and noticed all the piles of bones on the ground are all the undead he resurrects at the beginning of the battle. So I had Karlach run around to all of the bones, pick them up and toss them on one of the long chains that connects to the bottom of the battle area. I found it you threw them just off the edge, they actually respawn in the same spot they originally were. I then took the bones of the larger guys and brought them up the stairs and into the back of the area so I could quickly shove them off the edge at the beginning of the battle because I couldn't throw actually throw them like the smaller piles of bones. When the battle starts and all the bones that were thrown on the long chain are resurrected, they all immediately fall off. So the enemy count goes immediately from 30 or whatever crazy number to about 4. I love the versatility of fights in this game and how using the environment can totally change things.