Cosmic fire

Cosmic Fire, easily. Ultimate (Absolute) Burning can burn anything, and I do mean anything, even concepts and the like. Imagine being able to literally burn away your own limitations, or grant yourself an ability by burning away your lack of said ability.

I was thinking Nuclear and Cosmic, but decided Cosmic because Nuclear is limited in types of emissions of light and heat, while cosmic can make a small tiny flame, or the burning power of a star.