Piecemeal was created in a secret laboratory in the Amazon jungle. He was built to be the ultimate killing machine. Pieces of both human and animal corpses were combined with highly advanced weaponry to form the creature known as Piecemeal. The scientists who constructed Piecemeal were working under the supervision of the Red Skull. With the desire to create a weapon that could be employed against any superhuman foe, he planned to program Piecemeal’s mind before sending it out into the world, however, Piecemeal escaped and his mind is now in a blank slate.
Piecemeal was caught by X-Factor spying them on behalf of the new Genoshan government. He was confronted and easily defeated by Havok.
Energy-based form allows him to mold his body into any shape and appearance he can imagine and also absorb outside materials, adapt them into his structure, then dispell them in new forms.
Young Gilbert Benson was a mutant with the ability to absorb different energy frequencies and store them within his body. His mother, the armored mutant mercenary known as Harness who had been employed by Advanced Idea Mechanics, cruelly exploited this ability and forced Gilbert, whom she dubbed Piecemeal, to travel across the world with her to absorb the dispersed energy of Proteus, the deceased reality-warping son of geneticist Moira MacTaggert.
Absorbing the energy, Piecemeal grew larger and larger until he looked like a 700-pound monstrosity. The mutant team X-Force, alongside the New Warriors and a makeshift group of Muir Island-based X-Men allies, did their best to help siphon off the energy, but they failed. Finally, Gilbert's body exploded, and in that instant his mind combined with that of the reformed Proteus to form a new amalgamated being. The new entity set about warping reality all over Scotland.
The amalgamated Proteus/Piecemeal also captured their mothers and held them hostage as the pre-government-sponsored X-Factor team arrived. Finally, X-Factor convinced the boys to disperse their energies, consigning them both to oblivion.