Mad Jim Jaspers
Sir Jim Jaspers was a politician elected because of his anti-mutant and anti-superhero propaganda. However, secretly, he was a mutant himself "“ and an extremely powerful one for that matter. His entire propaganda was just a means to secure his place as a supreme being in his universe "“ something that he ultimately achieved, by using his reality warping powers and the adaptive cybernetic construct known as Fury.
His powers, however, ended up altering reality to such a degree that higher beings from the Multiverse ordered the destruction of Earth "“ and so it happened eventually, in order to prevent Mad Jim Jaspers' powers from altering parallel universes as well.
So, essentially, he was defeated only after the entire planet was destroyed.
Incredibly durable and resilient, this version of the supervillain was actually weaker than the one from the 616 Universe. As such, the mainstream Mad Jim Jaspers ended up being considered a omniverse threat. And there aren't that many supervillains who deserve this title.
Sure, he is mad "“ but that makes him even more dangerous.

