0.10.12 Win10 Some Astrologer perk causes Meraxis fight to end prematurely

Typically, my team would start casting at the beginning of battle, die from damage being reflected, but just keep casting until eventually they get resurrected or kill every enemy. Only when playing Astrologer, the fight is immediately over once all my creatures are dead. I assume this is related to some specific Astrologer perk, because I tried resetting my perk points before fighting Meraxis again and that time I won the fight as with any other specialization. I unfortunately don’t have the spare Keys to figure out which perk it is :confused: