One of my favorite Disney characters is Maleficent. The evil fairy of Sleeping Beauty. The Queen of all evil.
What is it that causes the villains to be evil, to be against the hero? What happened in their past to lead them to this stage? What are their thought processes?
What about Harley Quinn? Harlene Quintzel was interested in the thought processes of the villains of Gotham City and became Arkham’s psychologist. However, during her sessions with the Joker, she came to understand him, hate Batman, and love the Joker. She became Harley Quinn to give Joker laughs and lift up his day.