The Beyonder
The Beyonder is one of the most powerful beings in the Marvel Universe even though he is actually from beyond. He made his comic book debut in Secret Wars, a work by Jim Shooter, Michael Zeck, John Beatty, Christie Scheele, and Joe Rosen (letterer, ink, color). The enigmatic creature, who also abducted both good and bad people to compete against one another, built Battleworld.
As an invisible, nearly omnipotent creature from beyond the cosmos who abducted the Marvel Universe's heroes and villains in order to make them engage in combat on Battleworld. In the 1985 sequel Secret Wars II, when he assumes human form to learn about desire but threatens to obliterate the multiverse out of growing rage, the character takes on a more villainous role.
Beyonder has the power to change the nature of reality, as well as the states of energy and matter, as he sees fit. The Beyonder was essentially omnipotent, which gave him great power before a few retcons put limits on him. The Beyonder is currently a baby-like alien species, each of which has far more strong reality-altering abilities.
According to the narrator, his might was millions of times larger than the total power of the multiverse, and a typical universe was like a drop of water in the Beyond Realm. The abstract being known as Death demonstrated to be capable of being destroyed and recreated across the multiverse by the Beyonder, however it took a great deal of effort and damaged him to do so. He could still easily hurl an army of demons back to hell with a wave of his hand, even in this condition.
Creator: Jim Shooter