Mirror universe

A mirror universe is a plot item used in stories where a character or a set of characters are presented as their polar opposite selves for the most part. It is usually set in a universe where things are basically the polar opposite of how things operate in a story's normal universe.

Empath: The Luckiest Smurf stories
The EMPATH: The Luckiest Smurf story series has a Mirror Universe in it where the Smurfs (who are normally good) are evil and its Gargamel (who is normally evil) is good.