One of the Atomic Knights of earth-17, the Atomic Knight Batman is the Batman archtrope from his world. His exact origins are unknwn but is plausible to believe than mimics earth-0 Batman origin and to suppose he is the Bruce Wayne from his reality. At diference from the prime Batman, the Atomic Batman uses an armor than let him survive in the radioactive wastelands of Novamerika, where he follows his personal crusade, in the search of the Cosmic Grail.
His quest was interrupted when he was transported to earth-42, (via Transmatter Symphonic Array ), a world under the attack of the legion of Sivanas. After a battle against the robotic army of the Sivanas and discover the secret of the lil' league, Batman was summoned to the Hall of Heroes, where he joined the assembled heroes to stop the attack of the Gentry member Hellmachine and revealed the real nature of the chibi leaguers.
After the heroes in the satellite joined the forces on earth-8 to save Nix Uotan and the later discovering of the Empty Hand, earth-17's Batman choose to stay as a member of Justice Incarnate, not only to preserve the multiverse against the dark forces from earth-33, but also to expand his search of the cosmic grail to other universes.
His crusade still goes on.
Atomic Knight Batman appears in the story arc Multiplicity. Together with the Justice League Incarnate, they seek out Supermen in the multiverse forewarning them of an upcoming threat.