Superman / Batman #6

The World's Finest, Part 6: Final Countdown
The new Toyman has created a solution to the massive kryptonite meteor set to collide with the Earth... The Composite Superman/Batman Rocket Ship! But who should be the one to pilot it? As Superman is about to climb in to take the controls, a Boom Tube opens and Captain Atom emerges. He warns them that this is the mistake the Superman from the future tried to tell them about... Superman can't be the one to pilot the rocket! Using Batman's kryptonite ring (retrieved from the Batcave) Captain Atom neutralizes Superman and takes control.As Captain Atom pilots the rocket towards an unknown fate, Lex Luthor takes to the skies in Metropolis clad in a suit of power armor created for him in the firepits of Apocalypse. Raving, he calls Superman out and finally fights him man to man, as the fate of the planet rest in the hands of the Toyman and Captain Atom.
Release Date: 2004