What If: Beyonder
Okay, those of you who read Avengers: Illuminati know that there is an asteroid out there shaped like manhatten (plus some water) created by the Beyonder to play games on (Apparently Secret Wars II). What if he made a mistake. It was retconned that he was a mutated Inhuman who's reality warping abilities came from the combination of his natural powers and the Terrigen Mists. But obviously he's mortal. What if he made one mistake. What if when he dissolved the world, appearing to comply with Black Bolt's command and then reformed it one of his creations retained their memories. The only one who wouldn't be destroyed by being reverted to miniscule chunks of asteriod... Flint Marko.
Flint remembers everything, and in his panic over trying to cope with it, he accidently wraps a civilian into his mass... and they dissolve. When this happens he finds the memories of that person, realizing they only go as far back as the restart. He goes to the FF to figure out what's happening, as all the Beyonder's constructs don't realize what is Really happening. Reed runs some tests and comes to a dire conclusion. To test it he tells Flint to absorb a nearby metal table. While expecting it not to work, Flint is surprised to absorb it.
Reed glumly informs everyone that this world is a construct made of space dust, cosmic sand. This is why Flint remembers, the Beyonder forgot to cancel consiousnesses, he just dissolved everyone thinking it would kill them all. Well there was one person who could already do that: Flint Marko. Johnny, refusing to believe it tried to prove Reed wrong. Flint tried to stop him, but Johnny charged in. He was absorbed by Flint's body. Flint apologized abjectly, remorse being driven into by the minds he'd absorbed. He then realized he could now use Johnny's powers in conjuction with his own, meaning he'd never again have to fear by fused since he was now fire-proof.
The new Four (which include's Marko) set out to find out what is really going on. When enemies attack Marko tries to stay out of the fight, but does wind up absorbing a few more people. As the minds are added to his own, his thought processes change. He begins to realize that what's happening to them isn't really death, but in fact the only way they can live free, through him. He does his best to force it on no one, but it becomes less and less avoidable as they get closer to the Beyonder, who is enraged at his game getting away from him. Finally after beging blown backwards, scattering over Ben, Sue, and Reed and absorbing them, his mind begins to sharpen. and Reed's last independant thought to Marko is "You not some sand man anymore... your mass and location... I think we can call you a nebula, which Flint Marko takes as his new name. the more people he absorbs the harder it becomes to avoid absorbing them. He becomes massive, capable of penetrating the illusion, and using all his new powers in concert. When he absorbs the faux Galactus he becomes a true cosmic level being. Of course the fake wasn't on par with the real thing, but it is enough to tip his scales and allow him to truly face off against the Beyonder.