Waystalker or a Grail Knight with health regen duty really cripples Zealot in the most boring way.
Sure you can take damage and put yourself at low health everytime only to regen it back up again and lose your stacks.
Zealot is one of my favourite careers in the game, he is also the most boring one (in my opinion) if you play with full health or don’t completely make use of his stacks at low health.
This is probably not much of an issue with friends (got none) but for me that is mostly playing pubs it’s frustrating.
Maybe a feature that allows you to accept temporary health regen instead of health?