Final Crisis: Legion of 3 Worlds - Synopsis

Synopsis

The Time Trapper, after many unsuccessful attempts to remove Superman from history, retrieves a time-lost Superboy-Prime and sends him to 31st century Smallville. Superboy-Prime is enraged to learn of his minimal impact on history, while Superman remained a highly influential figure 1000 years later. Breaking virtually all of the Legion of Super-Heroes' enemies out of Takron-Galtos, Superboy-Prime leads them as a massive Legion of Super-Villains in a bid to destroy everything that Superman inspired, including the Legion and the United Planets. The villains travel to Sorcerers' World to recruit Mordru before continuing to Earth, killing Rond Vidar (former Legionnaire and the last Green Lantern) in the process. Meanwhile, the Time Trapper observes the assassination of Legion financier R. J. Brande.

The Legion of Super-Heroes, who are at half-strength and devastated by Brande's death, learn of the destruction of Takron-Galtos, so they summon Superman to their time for his help. While Superman leads the Legion into battle against the villains, Brainiac 5 (who was forewarned of Superboy-Prime's invasion by one of Dream Girl's premonitions) sets in motion a master contingency plan against Superboy-Prime that involves recruiting three of Prime's biggest foes.

First, Brainiac 5 sends Mon-El and Shadow Lass to take Rond's body to Oa and recruit Prime's nemesis, the immortal Sodam Yat (the last Guardian of the Universe), into the war. Brainiac 5 also sends three Legionnaires back to 20th century Smallville to retrieve a strand of hair from a young Lex Luthor and asks Starman to recover a body from a grave in the 21st century. Brainiac 5 himself ventures to the Justice League of America's old headquarters and uses their "Multiverse nexus crystal ball" to summon the Legions from two parallel universes, Universe-247 (the post-Zero Hour "Reboot" Legion) and Universe-Prime (the "Threeboot" version of the team), most of whom join the main battle against the Legion of Super-Villains.

Next, Brainiac 5, with the help of his own "Reboot" and "Threeboot" counterparts, use the lightning rod (empowered during the Lightning Saga story arc) plus XS running on a Cosmic Treadmill powered by the various incarnations of the Ranzz twins (Garth and Ayla) to resurrect another Superboy-Prime foe from the Speed Force: XS' cousin Bart Allen (Kid Flash). Brainiac 5 explains that the team of Legionnaires recently sent back in time (during "The Lightning Saga") used the lightning rod to "bottle up" Bart's essence before his death at the hands of the Rogues.

While Kid Flash joins the battle against Superboy-Prime, Brainiac 5 and his team travel to Superman's Fortress of Solitude for the final phase of his plan. They retrieve a Kryptonian healing chrysalis that was buried under the ice for 1000 years, placed there by Starman in the 21st century. The strand of Luthor's hair is placed in the chrysalis and the device resurrects Conner Kent, a.k.a. Superboy, who attacks his murderer, Superboy-Prime.

Meantime, Superman and the three Legion founders (Cosmic Boy, Saturn Girl and Lightning Lad) are forcefully taken from the midst of the battle to the End of Time by the Time Trapper, who is revealed as an aged Superboy-Prime. The elder Superboy-Prime reveals that he became an anomaly that could not be killed after being shunted into the Multiverse by the Guardians of the Universe and became the sole survivor of all creation. The founding Legionnaires use the Time Trapper's time portals to summon multiple Legions from across the Multiverse, who manage to knock the Trapper out.

The founding Legionnaires and Superman return to the 31st century with a recovering Time Trapper, who faces his younger self. Refusing to believe that the new arrival is his future self, and punches his future self, which causes both of them to vanish. The three Brainiacs reveal that the Time Trapper the Legion knew no longer exists as the future was reset when Superboy-Prime punched his elder self.

After the battle is over, the Universe-247 Legion, whose universe was lost in the second Crisis, decide to travel the Multiverse looking for other lost survivors, with Ferro naming the group the new Wanderers. XS and Gates decide to stay behind and join the original Legion. Brainiac 5 reveals to the "Threeboot" Legion that they are from Earth-Prime (Superboy-Prime's homeworld) after the Universe-Prime was recreated in the second Crisis. The two Legions depart, while Superman returns to the 21st century with Superboy and Kid Flash.

Meanwhile, an apparently powerless Superboy-Prime wakes up on the reborn Earth-Prime. He is reunited with his parents and his girlfriend Lori, who are all horrified by what he has become, having read all the comics he has appeared in since Crisis on Infinite Earths. Superboy-Prime begins to live in his fearful parents' basement while reading the last issue of Legion of 3 Worlds. He then turns and talks to the readers, insisting they knew he was meant to be Superboy before Conner. He then proceeds to troll the DC fan page on the Internet, remarking "They'll never get rid of me. I always survive."