Most villains, like heroes... result from circumstances. Something dramatic happens, which completely changes their way of being. The senseless murder of Bruce Wayne’s parents eventually led him to become the crime fighter famously known as “Batman.”
On the flip side of the coin, you have Oswald Cobblepot, aka “The Penguin.” The Penguin was once a nice guy, who was teased very much in childhood because of his short stature, obesity, and bird-like nose. These traits made him an outcast in his rich, debutante family. Their rejection drove him to become evil.
Hurt people mistreated villains, who were once good guys. Their transformation begins by seeking vengeance on all those who mistreated them. After everyone (in their mind) has been justly dealt with, they conclude others will eventually mistreat them as well. So, instead of giving them the opportunity to do as they believe, they begin the process of elimination. Eventually, giving people what they feel they deserve becomes second nature and creating new ways of doing it... exciting.
Their past selves remain buried deep within their subconscious. Something or someone brings it back to the surface... if for nothing more than a moment. If the villain’s a man, it’s usually a woman (mother, wife, sister, etc.), and vice versa, if it’s a woman (father, husband, brother, etc.).
None of us are born bad. This is a behavior that’s taught by people who learned how to do it... well. The skill of being bad is mainly fueled by pain, pain that was experienced physically, as well as mentally. Villains, feeling hurt, want others to experience their pain. Just my humble opinion.
Insightful