[Miller]

I have to agree with Miller, while I do think Painproof really does need more use cases, it's current use case is actually incredibly powerful, delaying a turn before you die can mean a substantial difference in a teamfight if you know your allies can't cover you.

Painproof and Body Of Isesip are taken on squishy characters to mitigate their disadvantage states and they both do very good jobs at that, but Painproof unlike BoI costs HP so its usage cases are a little less clear cut than normal.

I'm not actually sure what else to suggest for Painproof that I wouldn't already suggest for Ghost as a whole, HP costs converted into flat + current HP% instead of max HP%

Flat + Current HP% sounds like a nice way to nerf HP costs for it without getting into egregious territory once you hit low HP, I like it.