Because you like Rosemary Woodhouse in Rosemary's Baby
Jonathan Byers is a kindhearted outcast who tends to be in the wrong place at the wrong time. See them in Stranger Things.
Poison Ivy is a seductive, venomous botanist laments the fact that there are so many people to kill, yet so little time. See them in DC Extended Universe.
Leslie Knope can accomplish anything, literally anything, with a little grit and help from her office. See them in Parks and Recreation.
Armed guards, FBI agents, notorious serial killers – Hannibal Lecter has bested them all, with time to finish dessert afterwards. See them in The Silence of the Lambs.
Aang is already a master airbender and once he learns to manipulate water, earth, and fire, he'll be truly unbeatable. See them in Avatar: The Last Airbender.
Frank N. Furter is just a sweet transvestite with some not-so-sweet plans. See them in The Rocky Horror Picture Show.
Years of being a social outcast have taken a toll, but Elphaba is willing to be wicked if it means she can do good. See them in Wicked .
An aloof punk rock goddess, Nana Osaki has a surprisingly big heart. See them in Nana.
With his own ship, Peter Quill calls his own shots, and gets to fly from planet to planet blasting '70s pop hits and picking up alien chicks. See them in Marvel Cinematic Universe.
Clary Fray's philosophy: dive into the supernatural underworld first and ask questions later. See them in City of Bones.