WARNING: The following article contains spoilers for Justice League #32 by Scott Snyder, James Tynion IV, Howard Porter, Hi-Fi and Tom Napolitano, on sale now.
Scott Snyder and James Tynion IV's climactic, epic storyline "Justice/Doom War" has seen the Justice League encounter all sorts of surprising allies from across time and space, from the Justice Society of America at the start of the United States' entry into World War II to Kamandi and Justice Legion Alpha from divergent futures held by Brainiac. However, the most surprising -- and pivotal -- ally in the superheroes of the DC Universe's confrontation against Perpetua and the upgraded Legion of Doom may be one of the greatest villains in all of DC history: the Anti-Monitor.
Ever since the start of Snyder and Tynion's run on Justice League, the heroes have faced ancient, omnipotent beings from beyond the walls of the DC Universe following the destruction of the Source Wall at the end of Dark Nights: Metal. Among these figures is Perpetua, a Super Celestial from the Sixth Dimension and the otherworldly benefactor of Lex Luthor and the Legion of Doom, empowering each of the classic DC villains with new upgrades as part of her plans to bring the entire DC multiverse under her will.
Over the course of the series, Perpetua was revealed to be the mother of Monitor, Anti-Monitor and World Forger, and assigned them their respective realms to oversee in the Omniverse. Soon after Perpetua recruited Luthor following the breach of the Source Wall where she was imprisoned, it was revealed that Luthor wielded a piece of the Totality, a fragment resonating across time and space. Starman similarly has a corresponding fragment within his Cosmic Rod that can be used with other shards to imprison Perpetua once again.
Seeking assistance, Starman had successfully recruited both the Monitor and World Forger to join him against Perpetua while select members of the League traveled to the past and far-future to locate other fragments as part of their desperate plan. Approaching the Anti-Monitor in the hopes that his brothers can convince their estranged sibling to join them, Starman's plan appears successful as Anti-Monitor, Starman, World Forger, Monitor and Hawkgirl prepare to confront Perpetua at the close of the issue.
Ever since his creation by Marv Wolfman and Geroge Perez, the Anti-Monitor has been an unrepentant villain responsible for the death of untold trillions, nearly wiping out the DC multiverse during the Crisis on Infinite Earths. Later serving as a major figure within the Sinestro Corps during the Sinestro Corps War, the Anti-Monitor would return towards the end of the New 52 era as an antagonist opposing Darkseid when their respective quests to conquer the multiverse clashed. However, after years of destructive bids for total conquest, the Anti-Monitor may have finally been convinced to fight on the side of good for the very first time.
For months, Perpetua and the Legion of Doom have steadily been adding to their ranks and upgrading the familiar villains of the DCU with new, fearsome abilities. As the Justice League scours all of time and space for objects to give them an edge during the inevitable coming conflict, Starman may have just recruited the League's most surprising and pivotal ally in the Anti-Monitor. With the powerful master of the antimatter universe now among them, the League's plan to create a Justice Totality from other fragments of the Source Wall and imprison Perpetua once more seems like a distinct possibility... provided the heroes can first overcome the upgraded Legion in the past, present and future.