From Nobody to Nightmare

These are characters who started of as being normal citizens but later not only did they become villains but also became purely evil. This is not to be confused with a Fallen Hero who was once fighting on the side of good but becomes a pure evil villain. These type of villains were not originally considered a major threat until later in the story. They are also not to be confused with Hidden Pure Evils, who are originally believed to be good or neutral before showing their true colours later. Their opposites are pure goods who went from zero to hero.

Supernatural villains such as Deities, Cosmic Entities, and Demons almost never count because the status and magnitude of their power is inherently beyond what is normal, unless they were somewhat average/mundane before their corruption and happened to reach/exert a supernatural existence as they turned evil.