Lets do something fun, what would you be if you were a adventure time character ???

So this is basically just a OC making thing what would you be, how would you look like, some backstory, powers/equipment/powers and equipment, personality that kinda stuff Anyway if i was a adventure time character i'd really like to be a human wizard from before the mushroom war, i wouldn't have a constant form because i'd use magic to shape shift (unlike Jake i could not only look like a car but become one if i felt like it) mainly taking one of two shapes a giant black dragon(European mythology style not like ones from the show) a small black cat a dog (like a before mushroom war dog not a Jake like talking dog) and a tall blond human, i would normally fight in my human or dragon forms, in my human form i'd transform my arms in to swords for fighting and shape shift to be super buff, so as a basically immortal i'd spend some of my time messing with mortals when i'm bored but most of the time just act like a chill surfer dude the backstory: I (my avatar) learned magic a while before the mushroom war came, by that time i was already around 200 and spend most of my time messing around with mortals but after the war there were no humans left where i lived so i grew bored and held up at the local library till i red most of the books there, by that time a couple years had passed and the leftover humans were starting to show them selves so i figured since i had nothing better to do i figured i'd leed them... like a god... after a while came the rise of the vampires during which i played both sides and in the end both sides figured out what i was doing and back stabbed me as i had done to them, as i was weakened and now had not the power to protect myself from the vampires i fled so i could heal and hid among a tribe of humans.. a while passed and just as i was almost healed i met a half demon girl named Marceline from whom i learned of the existence of other dimensions. Once i was healed i traveled the nightosphere pretending to be a demon, then a dragon. As word of my abilities grew i was hired by Hunson Abadeer to be one of his enforcers. A long time later as i was growing bored of the nightosphere and being mad/evil i met one of Hunsons guests, peppermint butler who introduced me to death thinking we might get along. After meeting death we formed a band in the planes of death, but as i wasn't really dead yet and never felt like i belonged the're I moved to OOO and started a magical instrument shop, though at times i go mess around a bit around OOO