Because you like Kathryn Merteuil in Cruel Intentions

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.

Bucky Barnes used to be a good-hearted American soldier. Now he's the cold-hearted Winter Soldier. See them in Marvel Cinematic Universe.

He's the great Black Star, and he's come to assassinate you. See them in Soul Eater.

Konata Izumi has a live-now, worry-later view of the world. See them in Lucky Star.

Wei Shen is an undercover cop on a mission for justice (or at least vengeance). See them in Sleeping Dogs.

Misato Katsuragi is never without a beer in her hand or her pet penguin by her side. See them in Neon Genesis Evangelion.

Randy Marsh is a geologist and Nobel Prize winner who is into binge drinking, starting riots, the Food Network, and P.F. Changs. See them in South Park.

Handsome Jack is wearing a mask of his own face to hide his scarred real one. See them in Borderlands Series.

Armin Arlert was wrong. This world hasn't become hell; it's been hell. He just couldn't see it before. See them in Attack on Titan.

A ball of cheerful energy, Pinkie Pie is as sweet as her name suggests and lives to bring others joy with laughter and parties. See them in My Little Pony.

As the Rose Bride, Anthy Himemiya is a spectator in the fencing matches fought over her and her power "to revolutionize the world." See them in Revolutionary Girl Utena.

The only defense Earth has against alien invaders are giant robots in the hands of pilots like Kaworu. See them in Neon Genesis Evangelion.