Health-based ability (Hulk?)

Suggestion:
(apologies in advance if i'm duplicating a previous thread/suggestion )

I'd like to see a character with an ability whose power is proportional to their health.
In otherwords, as their health gets lower, their ability gets stronger.

This could lead to some interesting strategy...

I could see a future Hulk character with such an ability...
You'd have to finish him off quick, because at low health he'd be straight rage'n and pack a whollop!