make vomiting more impactful

[Angel]

I feel like stuns would be a bit much, with how easy it is to force someone to be constantly vomiting, with stuff like port-a-puke, or even just that one medical chemical that makes you vomit. Instead, maybe vomiting takes some stamina (around 30 seems fine, that's around the amount of stamina you usually lose when you get hit in combat), and it also deals some minor burn (since vomit is acid, and IRL vomiting too much can cause ulcers).