Saw your BRD run. Can't lie, I was getting a bit agitated watching you standing still and tanking Thaurissan's enrage with your mages.
As a tip, you can polymorph princess so she doesn't kill your healer or heal the emperor. You can also use the platform the boss starts on to force him to path around and not be able to melee you during his enrage. If you use counterspell on the mage you want to dodge with it causes a high amount of threat so you can ensure which mage receives aggro in order to dodge with him.
Watch this:
https://www.youtube.com/watch?v=DXEt2eCD7IQ
Might as well kite during this phase since he's immune to magical damage during enrage anyway.