It would be interesting to create the reverse of this template as well, The James Dean template if you will (can't think of any satisfying antonyms for immortal at the moment). Effectivy it would need to be a creature that gains great power at dramatic speed, but at the cost of any chance to live a long, normal life. They know that they won't survive their current age catagory (or some such), fate guarentees their death, one way or another, but that allows them to unlock hidden stores of energy within themselves, or perhaps even access fate directly.

I'm trying to think of appropriate mechanics, but if anyone else thinks its interesting and wants to take a crack at it please be my guest.