He will grab a skeleton to heal tim toe time - aoe them down, should be easy - Corpse carrier summons skeletons as well - just aoe/farm them - make sure all skeletons are removed from the arena if your struggling dpsing the boss with uberheals.Don't trust a rose by it's appearance, it's thorns will still sting you.
It's the same with humans, some have opinions and some are just crazy.
When he summons the ogres he heals - you can't prevent that.
Otherwise he sacrifices all skeletons from time to time gaining a few thousand health points for each one. You can prevent that by destroying the portals and killing the skeletons before he does that.Improvements: Tooltip / (F2P) QoL v2 Quick Fixes: Invention