It's a super hero cartoon about a kid with no powers in a school full of super heroes with powers. His friends also have powers (and I'm pretty sure one of them was a goth girl, she became the queen of slugs in one episode)
The main character's hero costume was a cape and an underwear outside of his pants and the recurring villain was a janitor with a robot minion that looks like it was made with house objects. Every time he becomes evil he just wears a cape.
At first I thought it was World of Quest because the art style was pretty similar, but no it wasn't.