Well, not to jump on the power hate bandwagon but:

Shortening his life span to use it isn't a great balance either.  Like giving other people bad luck, it's easy for the player not to care about it.  It's not like the game is going to go on long enough for him to die early, unless we keep rigorous track of his power usage and how much of his life it takes off.  And if we do that, eventually he won't be able to use his power anymore and he'll just be useless.  

Probably it's best to wait for Knight to propose his own balance for the power.