Because you like Ash Ketchum in Pokemon
How lucky are we that Arthur Curry, the King of Atlantis, hasn't taken over the surface world? Very! See them in DC Extended Universe.
The vampire that killed Zero Kiryu's family also infected him, and he starts to crave blood, much to his horror. See them in Vampire Knight.
A jaded skeptic who only wants to get paid, Garrett becomes involved in bigger struggles that force him to be less self-serving. See them in Thief.
Once a loving family man, James Heller is now dark, damaged, and hell-bent on getting revenge. See them in Prototype Series.
Years of brutal winters, foreign invasions, and crippling loneliness have left Russia's mental state far from wholly intact. See them in Axis Powers Hetalia.
Foul mouthed and disturbingly comfortable with violence, Hit-Girl is a precocious assassin who doesn't need anyone's protection. See them in Kick-Ass.
Tail's smarts and helpful nature come in handy in a pinch. See them in Sonic the Hedgehog.
Leonardo is spiritual, and devoted to more than just pizza. See them in Teenage Mutant Ninja Turtles.
As the hero of time, Link is reborn throughout history, always with the purpose of fighting and defeating the evil Ganon. See them in The Legend of Zelda.
Kyoya Ootori is possibly the only person who could reasonably go from VP of a school club to ruling the world. See them in Ouran High School Host Club.
