Back when the world was young, Kilroy the omnipotent coupled with a volcano unknowingly. The volcano, unable to contain the insanity on Kilroy's offspring, ejected the product into the sea. The product was a child.
The child sank beneath the waves. Down and down it sank, until it fell upon a school of demon whales. The whales could sense the power within the child. They took it, and the leader ate the damn thing.
One day, the whales all died. From the stomach of the largest whale came a high pitched pig squeal. Then the whale burst into a million parts, and from the wreckage strode RANDY ROCKET.
In his hand he grasped a guitar of whale bone, a magic guitar that held the souls of the demon whales. On his head was the most delicious mohawk you will ever see. It was blazing orange, like the fiery temptress that spawned him.
Randy ventured to the surface of the world and claimed his rightful place in the pantheon, by right of birth. Now he resides on top of Mount Rockenstein, in a concert hall of pure steel. He rides a flaming beast of power metal when he needs to go out.
Randy's domains are rock, battle for glory, freedom, and sex. Lightning's his thing too. His followers are the young men who go from town to town, rocking out and bedding the sweetest maidens around. Then they pick up and leave without another word. His templars are the black clothed warriors of the night, stalking the shadows, dealing death to his hated foe's minions, Berry McButskoot, the lord of pirates and butt sex(The nasty kind).
Randy rocks it out in the Medieval, Renaissance, or Dark Age. I don't really know the difference.