Because you like Martha Jones in Doctor Who

Leonidas is not the kind of king who merely gives orders; rather, he's out on the battlefield fighting alongside his men. See them in 300.

Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.

An infamous vampire, Alucard is a one-man killing machine with a philosophical side. See them in Hellsing.

Bad-ass Rayne has sworn her life to finding and destroying her vampire dad, Kagan, and killing as many other vampires as she can in the bargain. See them in BloodRayne .

While Alan Garner is loyal to his new friends, his efforts to help them often do more harm than good. See them in The Hangover.

Eren Jaeger will erase the Titans from this world until not a single one remains. See them in Attack on Titan.

Damon Salvatore used to miss being human. Now he can't think of anything more miserable. See them in The Vampire Diaries.

An ironic hipster with a healthy dose of self-deprecation, Dave strives to be cool at all costs. See them in Homestuck.

A good-natured and academically minded superhero, Dan Dreiberg can still get his hands dirty in a fight. See them in Watchmen.

He may be one of the Four Horsemen of the Apocalypse, but War still maintains a strong sense of honor. See them in Darksiders Series.

Once a loving family man, James Heller is now dark, damaged, and hell-bent on getting revenge. See them in Prototype Series.

For the sake of science, Kurisu Makise will persevere no matter how deep into the dark secrets of the world she finds herself. See them in Steins;Gate.