http://www.best-ever.org/download?file=redhealthv1a.pk3
Had this idea a while ago, was spurred on by the erosion mechanic in that mod Stardust made.
Based off of red health from fighting games, each time you take damage, your max health decreases. The amount that is recoverable is "red health."
Intended this for duel in order to ensure that matches progress, but I don't thing the duel guys will go for it.
Maybe I can work it into some sort of lms mod down the line.
(http://i683.photobucket.com/albums/vv191/JaxOf7/Screenshot_Doom_20160103_123005.png)