One day, a man accidently fell in a volcano while visiting Hawaii. To his surprise, his body was not burned at all (but his clothes all burned off). Something must have changed then, because he found he could create lava out of his left hand. He climbed out of the volcano, put on a purple mask, and fights criminals using his abilities.

Strength

Immune to heat.
Left arm can erupt with lava.

Strength Source
Falling in volcano.