Vulcan

An Omega level mutant, Vulcan is the lost brother of Cyclops and Havok (two of the most well-known X-Men). He has a pretty tragic origin story, being torn out from his dead mother's body by the Majestor of the Shi’ar Empire. Sent back to Earth, he escapes the Shi'ar and becomes an X-Men, where he is takes on various missions.

In one of them, against the living island Krakoa, he is believed to be dead "“ along with a few fellow X-Men. But he wasn't. After fighting the X-Men who left him for dead and after easily defeating them, he heads into space, after remembering how he was torn out of his mother's body. His intention is to defeat the entire Shi'ar.

And he does that, becoming the leader of the empire "“ the first outsider to do that.

He has a pretty large array of powers. But his greatest strength is that he is able to absorb any and all amounts of energies. At one time, he even forced Adam Warlock to flee, after completely depowering him.

He is also resistant to telepathic attacks and he also possesses telekinetic abilities. At one time, he was even able to manipulate time itself (after revealing that he wasn't dead).

Vulcan is so powerful, having complete control over fire, earth, electricity, wind, water, darkness, and light, that he is on par with superheroes such as Silver Surfer and supervillains such as Onslaught, having the potential of surpassing any of these.