I'm a god. I will live forever.
~ Hades
My form is justice. My form is the world! Revere me. Praise me. The noble and beautiful, immortal and most powerful god, Zamasu!
~ Fused Zamasu's birth

Villains who are Deities (Gods) and have override the most greatest toughest possible level of power so great they are equal to such cosmic beings. Needless to say, these are some of the most powerful villains of all due to their nature.

To count as a deity, a character should also have been worshiped, either in the past or present; some deities may even require said worship to function. Sometimes, these beings rule the cosmos and do not want anybody to rule in their place.