Because you like Inigo Montoya in The Princess Bride
Nadine Franklin likes to wallow in her misery almost as much as she likes to torment her mother. See them in The Edge of Seventeen.
When the Sorting Hat touched Draco Malfoy's head, it placed him in Slytherin, a house that has turned out more dark wizards than any other. See them in Harry Potter Series.
Talented but anxious, Shinji Ikari struggles to bear the challenges that life hands him. See them in Neon Genesis Evangelion.
Ichigo Kurasaki is a short-tempered, strong-willed teen who is deeply protective of those he loves. See them in Bleach.
Patrick's time as a fake psychic made him a master manipulator. But he now seeks to only use his talent for good. See them in The Mentalist.
The core of Satoru Gojo's techniques lies in Limitless, a method that uses cursed energy to control space. See them in Jujutsu Kaisen.
Wei Shen is an undercover cop on a mission for justice (or at least vengeance). See them in Sleeping Dogs.
Whether she's working as a mild-mannered assistant or an all-powerful superhero, Kara Danvers is defined above all by her huge heart. See them in Supergirl.
Light Yagami has a plan to make a better world, and morals won't stop him. See them in Death Note.
Courteous, dangerous, and powerful, Kaname Kuran controls an entire court of vampires. Very, very pretty vampires. See them in Vampire Knight.
Always headed towards adventure, Goku is frequently with a band of loyal companions at his side. See them in Dragon Ball.
Did he ever tell you the definition of insanity? Just wait, and this psychopath will do just that. See them in Far Cry 3.