Because you like The Wicked Witch of the West in The Wizard of Oz
A champion of chivalry, Don Quixote is dutifully bringing good to the world—even when others think he's out of his mind. See them in Don Quixote.
Major Marquis Warren is a talkative, sharp-eyed, and cold-hearted Civil War soldier-turned-bounty hunter. See them in The Hateful Eight.
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 .
Anywhere there's adventure, Jaskier is there to write a catchy song about it. See them in The Witcher.
Diana Prince is using a truth-telling lasso and super-strength to make Earth a little more like Paradise. See them in DC Extended Universe.
Chanel Oberlin is a big fan of herself, and she can't see why anyone else wouldn't be too. See them in Scream Queens.
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.
The only constant in Night Vale is Cecil's hypnotic voice. See them in Welcome to Night Vale.
Stanley Barber is a loveable goofball with impeccable (if eccentric) fashion sense, unique music taste, and a wealth of strange but useful knowledge. See them in I Am Not Okay With This.
The only thing Albert Wesker cares about is turning himself into a God. See them in Resident Evil Series.
Raz is a 10-year-old boy who mostly stays in his own head, which makes sense since that's where he is strongest. See them in Psychonauts.
Beware! Anton Chigurh carries a coin with him, which he forces his victims to flip to decide whether they will live or die. See them in No Country for Old Men.