WARNING: The following article contains spoilers for Justice League #33 by Scott Snyder, James Tynion IV, Bruno Redondo, Daniel Sampere, Juan Albarran, Hi-Fi and Tom Napolitano, on sale now.
As the Justice League's battle against Perpetua and the Legion of Doom for the fate of the DC Universe intensifies, the team has scattered across the DCU's past and alternate futures, finding familiar allies across time and space. A portion of the team, including Superman, Batman and Wonder Woman, had arrived in the post-apocalyptic future featuring Kamandi, the last man on Earth. As the League explored this strange vision of their potential future, they discovered it was one of many divergent futures held captive inside of a containment bottle by Brainiac One Million.
Receiving additional support from Justice Legion Alpha, the far-future super-team from DC One Million, the Justice League faced the futuristic villain directly while Kamandi searched the various imprisoned alternate futures for reinforcements. The final pages of the latest issue of Justice League brings Kamandi face-to-face with a fan-favorite DC team from tomorrow, Justice League Beyond.
Set decades ahead of the relative future of the DCU, this team hails from the future of Batman Beyond and makes their DC Rebirth-era introduction here.
The Justice League Beyond was introduced in the third and final season of Batman Beyond, led by a decades-older Superman along with Big Barda, Warbird the son of Hawkgirl and Green Lantern John Stewart, the Buddhist monk Green Lantern Kai-Ro, Aquaman's daughter Mareena, an adult Static and the size-changing Micron. The team would later reappear in several episodes of Justice League Unlimited set in the future of Neo-Gotham and continue their own adventures in a comic book series by Derek Fridolfs and Dustin Nguyen.
The comic series had Superman temporarily lose control of himself and powers, pitting him against his teammates in a battle for the future before facing their true foe in the exiled Kryptonian criminal Jax-Ur. The arrival of Jax-Ur would lead to the return of General Zod who, in a surprise move, joined the team, since the future version of the DCAU's Brainiac returned and attempted to reshape Earth in his image. The Justice League as the last line of defense to protect the planet from his iron grip. The finale to the comic series had future incarnations of the Justice Lords -- an totalitarian group who ruled their alternate Earth -- attempt to extend their rule to the main DCAU Earth once again.
It is unclear how much of the continuity from the previous comic book series remains intact in the DC Rebirth incarnation of this version of the Justice League Beyond. The assembled characters appear as they did at they did in Justice League Unlimited and there's no indication whether it's Terry McGinnis or the adult Tim Drake -- who briefly held the mantle of Batman Beyond during the New 52 era -- under the cowl, or even if an elder Bruce Wayne is still alive and observing his protege from the safety of the Batcave.
The "Justice/Doom War" has brought together several notable DC superheroes from across time and space, including Kamandi, Justice Legion Alpha and now Justice League Beyond. With the fight against Brainiac One Million continuing for the fate of the DC Universe's divergent futures, every notable future incarnation of the DCU has shown up so far, save for the heroes of the Legion of Super-Heroes and Kingdom Come. With the Justice League Beyond now in the fight, the heroes have continued to bolster their ranks for the final battle.