[@Retired] My John Jones I was considering doing was from an old Young Justice RP, but I'm less keen on doing that one right now because I will probably be playing an alien in another game.

I'll run by you which idea you think you'd rather see.

Kid Apocalypse is a "toy left out of its box," an ancient experiment by the Celestials to combine their technology with the limitless mutagenic potential of the X-Gene. The cells of his body are made from living metal nanomachines, which he can manipulate into different configurations. Essentially a T-1000 that can copy mutant powers. In any case he was left dormant deep underground after his creation, and what awoke him was some kind of apocalypse taking place on Earth. He emerged into a ruined Earth, and eventually formed a "tribe" of survivors that he protects and leads through the wasteland.

John Jones is also a psychic shapeshifter, but is an alien infiltrator dispatched by the Martians to colonize Earth. He was implanted into his mother after she was abducted by a UFO, and she gave birth to him and raised him not realizing that he was a pink grub and not a human baby. A mix of shapeshifting and subconsciously-broadcast hypnosis kept others from realizing he wasn't human his entire life, including John until he was a teenager. The revelation that he wasn't human, just some kind of monster pretending to be, was a such a shock to him that he became a teenage delinquent. He's unknowingly waiting on a psychic signal from Mars that will activate him as well as the other sleeper agents on Earth, but the ongoing Martian Civil War may complicate that.