Pokécharms

There are canonical Pokemon that can use recovery moves like Recover or Heal Pulse or the sort. Keep in mind that so long as you don't godmode, a healing power isn't too farfetched.

Well alright, thank you. The ability to reverse all damage and healing taken for like a couple of turns had me pondering there a little too much...

That MIGHT be too much, tbh. Canonical healing moves generally recover about half of the user's maximum HP - which may be a a good number of hits taken, but it may not - depends on the damage taken. Also keep in mind that Gameplay and story segregation elements would mean that damage would not be assessable so easily in terms of percentages.

So basically, you can recover to some extent but don't expect an easy complete health reboot - that might JUST be too godmody.