Originally Posted by
Plasmon
Sorry, I don't know anything about the main topic of observing vengeance cap lower than the 10% of HP thing... but this effect that Elunedra noticed, I don't believe is a bug.
I think hits that are supposed to do a "percent of target's health in damage" are pre-mitigation, but likely either ignore armor if they are physical damage or they might more often be spell damage, possibly ignoring resistance. How bears still reduce the magnitude of that damage is from the 12% damage reduction from the Natural Reaction talent, and if it's spell damage then also the 6% spell damage reduction from the Perseverance talent. (and Barkskin too if you use it before the hit)