Lavos, hands down. he destroyed the world, and it took a spikey haired swordsman gathering up such great forces as his Best friend - a genius AND practically a fire goddess, a badass robot, a knight turned into a frog, a prehistoric babe and a merciless magician.
And after all that death, He still comes back with the ability to destroy everything.
Baa baa black sheep have you any booze? No sir, no sir, I'm a....sheep~