In hell, there's a metal band call "Hellfire Annihilation" and he's once the member of this band. But after sometime he realise that the direction of this band going is not what he want. Metal music not suppose to serve the evil purpose, music is pure art and good in his idea. So he's left the band and get out of hell.
Even though he's one of the evil entity that raise and born in hell, now he use his talent in metal music and power of hell to do good deed, and become...
"Metal Hero"