Beyonder

The Beyonder is an infamous member of the Beyonder race. Childlike and vastly powerful, he grew up in a universe created by the other Beyonders for their young. He was not aware of other Beyonders and misinterpreted his personal universe as everything in existence. While still a child, the older Beyonders began their grand experiment where they transformed Owen Reece into the "Molecule Man"; this "accident" poked a hole into the Beyonder's universe.

Having observed Earth, the Beyonder started various "Secret Wars": He created Battleworld and forced many heroes and villains to fight. Later, he gave himself human form to experience the Marvel Universe. He eventually threatened to end existence but accidentally allowed himself to get killed, or so it seemed. His energy returned to his realm where it evolved into a new universe. After being visited by Kubik and the Shaper of Worlds, two sentient Cosmic Cubes, the Beyonder merged with the Molecule Man to become a new Cosmic Cube.

His time as a Cosmic Cube was short-lived and he eventually returned to being the Beyonder. According to him, he was a kid that was broken and becoming a Cosmic Cube was meant to "fix" him and speedrun through certain larval stages. Now fully-grown, he lived with his fellow Beyonders in the Beyond, until he escaped the House of Ideas.