I tweaked it a bit:

HEAVY METAL: The protagonist arrives on a Harley, kills the dragon, drinks a few beers and bangs the princess.

POWER METAL: The protagonist arrives riding a white unicorn, escapes from the dragon, saves the princess and makes love to her in an enchanted forest.

FOLK METAL: The protagonist arrives with some friends playing accordions, violins, flutes and many more weird instruments, the dragon falls sleep (because of all the dancing). Then they all leave… without the princess.

VIKING METAL: The protagonist arrives in a ship, kills the dragon with his mighty axe, skins the dragon and eats it, robs the princess and burns the castle before leaving.

DEATH METAL: The protagonist arrives, kills the dragon, fucks the princess and kills her, fucks her again, then leaves.

BLACK METAL: The protagonist arrives at midnight, kills the dragon and impales it in front of the castle. Then he sodomizes the princess, and drinks her blood in a ritual before killing her.

DOOM METAL: The protagonist arrives, sees the size of the dragon and thinks he could never beat him, then he gets depressed and commits suicide. The dragon eats his body and the princess as dessert.

PROGRESSIVE METAL: The protagonist arrives with a guitar and plays a solo of 26 minutes. The dragon leaves out of boredom. The protagonist arrives at the princess’s bedroom, plays another solo with all the techniques and tunes he learned in the last year at the conservatory. The princess wishes he was the HEAVY METAL protagonist.

GLAM METAL: The protagonist arrives, the dragon laughs at the guy’s appearance and lets him enter. He steals the princess’ make-up and tries to paint the castle in a beautiful pink color.

NU METAL: The protagonist arrives in a run-down Honda Civic and attempts to fight the dragon but his baggy clothes catch fire. The recording of his screams sell millions of copies.

GRINDCORE: The protagonist arrives, makes weird screeching noises for about 2 minutes and then leaves.

INDUSTRIAL METAL: The protagonist arrives wearing a greasy overcoat, flips off the dragon and gets escorted out by security guards.

EMOCORE: The protagonist and his friends get a ride from his mother to the castle. He kills the dragon with some awesome arm-spinning and spin-kicking while his friends watch with their arms crossed. The princess laughs at the protagonists ridiculous hair and the boys leave in tears, saying she was a bitch anyways so whatever.

PUNK: The protagonist hitchhikes to the castle, asks the dragon for some bucks, buys some cans of beer, gets pissed, calls her a “monarchist cunt” and “commerce bitch” and leaves the castle on the city bus.

POP ROCK: The protagonist arrives in a limo. The dragon lets them in as long as they sign an autograph for its mom who is a big fan. The protagonist leaves with the princess and they get married for a total of 3 days. The protagonist writes 2 albums about her.

GOTHIC METAL: The protagonist arrives along with a cold wind of winter in the middle of the night, frustrates the heck out of the dragon until it dies of fear and desolation, comes to the princess and asks her how to remove makeup without clogging his pores.

METALCORE: The protagonist does some epic headbanging, accidentally knocking the dragon out. Then he storms off in anger because the dragon wasn't supposed to be defeated until the 3rd song

COMEDY METAL: The protagonist happens to be Jack Black, and fucks the dragon while singing about his kielbasa