exhaustion linked to hitpoints

Possibly a crazy idea but hear me out— I’m starting a group that will be playing in-person one-shots. I have a couple ideas to make these one-shots interesting and to encourage players to experiment with new ‘disposable hero’ characters.

  1. Killing is deadly. as in, if you kill an enemy, you will likely die (because of the gods or some curse on the land, whatever)
  2. At half HP, all creatures (monsters or characters) gain a level of exhaustion. it increases as more HP is lost (it’s going to take some experimenting to figure out how much—and probably bosses have some degree of exhaustion resistance)
  3. Drinking water or eating food reduces exhaustion.

I would be offering pre-generated characters to take the sting off of dying (in any case where players deem an enemy worth finishing off)

I just like the idea of even monster death being something reserved only for the really bad ones— and having exhaustion of most enemies as a goal just feels more impactful, makes the fight against evil feel like an evolving situation.

I feel like this could work, but i’ve never tried homebrew rules that could be so game-changing. The main thing is of course that I want everyone to have fun.

I would really appreciate any suggestions or feedback before I try it out, well, that is, if my new party is on board with the idea.

I’ll let you all know how it goes!