villain origin

A villain origin is the backstory explaining how someone became evil or antagonistic—the trauma, betrayal, or circumstances that transformed an ordinary person into a nemesis.

The term comes from comic books and superhero fiction but now applies broadly to any explanation of why someone turned bad: His villain origin was getting passed over for promotion three times.

Often used humorously to describe minor grievances that might theoretically radicalize someone: Watching people not return their shopping carts is my villain origin.