I know you can reduce the regen delay to 0, but I'm trying to make percent based stamina regen through damage.

I've tried changing the gamesettings to -1, my guess is the regen delay is hardcoded. It would make my life easier if it isn't though. I can work around this but being able to use the existing regen system would make my life SOOOO much easier.

Thanks for your time

Your best bet is to look for a Fortify ability, such as Fortify Health, and use that as a base for a new Magic Effect-- "ReduceStaminaRate". From there, check the 'Determinal' and 'Hide In UI' Checkboxes. Set the Associated Item (which in Fortify Health will say 'Health') to 'StaminaRate'. Then just make an Ability with a magnitude of about 1000, and add it to the Player.

I've never tried it with Stamina, but it works perfectly for Health and Magicka to stop the natural regeneration there, so it should work the same; you can still restore via Restore Spells and RecoverAV.