After this creature provokes, it gains 100% current and Maximum Health. When it stops provoking, it loses 50% of its Maximum Health.
I’m currently playing as a nature mage with the +50% boost to health, speed, defense.
I also have +5% health from mage perks.
Nothing else should be impacting maximum health.
When my Giant Mangler provokes, he gains something like 60% maximum and current health rather than the stated 100%
It gets extra weird when he stops provoking, because his maximum health changes to a value 10% or so lower than when he started.