WARNING: The following contains spoilers for Generations Forged #1, by Dan Jurgens, Andy Schmidt, Robert Venditti, Mike Perkins, Marco Santucci, Paul Pelletier, Norm Rapmund, Bernard Chang, Joe Prado, Colleen Doran, Bryan Hitch, Andrew Currie, Kevin Nowlan, Hi-Fi and Tom Napolitano, on sale now.
While DC's most iconic characters made their debut in the 1930s and '40s, the main DC Universe canon introduced many heroes during the Golden Age that remain in their physical prime, continually updated as they move along a sliding time scale to better entertain each generation of readership. One hero that has maintained an awareness of the universes and realities that came before is Batman, who kept a letter written from his father Thomas Wayne during the Flashpoint reality in the Batcave throughout the New 52 era until the start of DC Rebirth.
And as a Golden Age vision of the Dark Knight assists the heroes in protecting the space-time continuum in Generations, he walks away with one of the most powerful devices in the DCU in his possession: A time-band.
The heroes of Generations were assembled by Waverider and an older Booster Gold to protect the various fracturing timelines from the villainous Dominus. Among the heroes to witness the reality-warping effects of Dominus' machinations firsthand is Batman, whose present-day adventures through Gotham City abruptly transformed into 1939. Bruce Wayne retained no memories of his more modern life before he is recruited to join the time-traveling team. After their victory, Waverider and Booster decide to give Batman one of their spare time-bands while to him why he remains largely physically unchanged over time.
Characters like Batman and Superman are updated over time while Justice Society of America heroes like Jay Garrick and Alan Scott visibly age because Bruce and Clark are figures in what Waverider refers to as the Linearverse. These icons maintain their youth and vitality for decades, expanding on Doomsday Clock's ideas about time distortion. As Superman resets with every great cataclysmic event, so does the world and characters around him. While the Caped Crusader wasn't as centrally identified as being a part of the DCU's meta-textual reality, Waverider's explanation does provide an in-continuity reason for him keeping up with Superman over the decades since their debut.
Armed with a time-band, Batman can now travel to any point in the DC's shifting timeline. As Batman returns to his own time, Waverider warns him that the time-band should only be used as a last resort and that a true crisis is coming for the DCU that will require his services and his new weapon, effectively leaving the Dark Knight with more questions than answers in the aftermath.
The time-bands were a vital tool used by various heroes and villains in the Arrowverse to travel through time and space, and now Batman has become the latest wielder of one such rare device in his possession. More ominously, the time-band is strongly suggested by Waverider to be a vital part of the heroes' defenses when a crisis of unknown origins and nature comes for the entire DCU, even bigger than the threat posed by Dominus. Dominus nearly completely upended history across multiple timelines. Armed with a time-band, Batman needs to be prepared for something far worse on the horizon.