User can manipulate fire.

Pros:
-user can create fire storms
-user can control heat
-user can become a human fireball
-user can fly using fire
-user is immune to fire attacks

Cons:
-fire storms take a lot of energy
-user can't control light
-user will need a special suit under clothes to not be naked after burning clothes
-user can harm others with fire
-user will be constantly warm

Weakness: water/ice
User will be put out, so no fire :(