Is there a way to change base stats for just my team

[Nosnos]

So I’m planning on doing a Pokemon emerald/ruby/sapphire challenge run where all my Pokémon only have one hp for the entire run. Is there any way to do something like that. I don’t want any wild or trainer Pokémon to be affected by it either. Is it possible? 

[jacksonf]

I think you can use EKHeX (a fork of an older version of PKHeX for Emerald Kaizo) on vanilla saves. There you can set statuses to your mons. It may end up being extremely annoying but you can poison them and move around until they're at 1HP and get rid of the status.

[Shady Guy Jose]

You're probably better off using a tailor-made Action Replay/Game Shark code to make your current HP 1 at the beginning of each battle (maybe with a key combination to trigger it, or something). I can't make you one myself, but there should be people around here with the skills to do so.