Also worth noting that there could be a difference between what your character uses in combat and what they are actually capable of. You could think of it like the difference between how hard you could throw a baseball and how hard you could throw it without injuring yourself. how much are they holding back to avoid injuring themselves or their allies?
Now granted there is potential for storybreaker powers in this but it also opens a door for exploring what a character can do that for whatever reason cannot be done in the chaos of combat. Maybe a certain ability requires too much concentration/windup/fancydresses, maybe they have to spend effort keeping it from eating your buddies, maybe it just turns their teeth purple. It could even be that they can ONLY do neat stuff in combat and out of it they’re just a regular fellow .