The Justice Legion is a super-hero group of the 853rd Century descended from the Justice League of America and the Legion of Super-Heroes, and are charged in protecting the galaxy. The Justice Legion consists of at least twenty-four Legions and among the highest ranking is the Justice Legion Alpha.
The Justice Legion Alpha traveled back to the 20th century to invite the original Justice League to join them in celebrating the return of the original Superman, Superman Prime, from his seclusion in the sun. The Justice League agreed in joining the Legion, but as soon as they travel to the future the Legionnaire member Hourman became corrupt with an infectious technovirus by the 853rd Century Vandal Savage and a traitorous Starman. The "Hourman virus" began infecting every living being on 20th century Earth, eating away at their mental and physical functions. The virus also affected Hourman to strand the Justice Legion in the 20th century while the Justice League were trapped in the future. The Justice Legion helped the present day heroes to creating a containment for the virus, which inevitably led to the creation of the evil super-intelligent stellar computer Solaris, as the virus was originally sent to fulfilled.
Upon completing the structure, the virus vacated the people of Earth and ignited the newly-formed cyber star. During this, the Legion discovered Starman's betrayal but allowed him to atone for his crimes. This act of faith, added to Starman's enlightening conversation with his ancestor, Ted Knight, led him to save Earth from Solaris by using his cosmic rod to compress Solaris into a black hole at the cost of his life. The League in the 853rd Century further learned about Vandal Savage's alliance with Solaris and their intention on killing Superman Prime with the only piece of Kryptonite that was left implanted in the past by Starman. However, Savage was unaware that the Kryptonite was destroyed by Starman upon his reformation in the 20th century, and instead the Justice League tricked Savage into taking Green Lantern's time lost power ring. Just as the ring was launched into the sun, Superman Prime emerged and helped Green Lantern in containing Solaris by forcing the sun to go supernova, then contain it until it burnt all of its hydrogen and went dormant. Savage attempted to escape, but teleported to the 20th century, right at the detonation of the nuclear bomb at Montevideo, Uruguay. Ironically, this bomb had been launched by the 20th century Savage.
There are apparently 24 Justice Legions. Those featured include:
- Justice Legion A: The premier team which is based on the Justice League.
- Justice Legion B: Members include Nightwing (a batlike humanoid), Aqualad (a humanoid made from water), Troy (a younger version of Wonder Woman One Million), Arsenal (a robot) and Joto (killed in teleporter accident). They are based on the Titans.
- Justice Legion L: They are in charge of protecting an artificially created planetary system (all that remains of the 30th century United Planets). Members include Brainiac 417 (a disembodied intelligence with the powers of Brainiac 5 and Apparition), The M'Onelves (who combine the powers of M'onel and Shrinking Violet), Implicate Girl (who contains the abilities of all Cargggites in her "third eye", very loosely based on Triad), Titangirl (psychic energy of all Titanians, based on Saturn Girl), Cosmicbot (a cyborg based on magnetism, based on Cosmic Boy), Dreamer, Chameleon, and The Umbra. They are based on the Legion of Super-Heroes
- Justice Legion S: consists of numerous Superboy clones, all with different powers. Members include Superboy 820 (with aquatic powers), Superboy 3541 (who can increase his size) and Superboy One Million (who can channel any of their powers through "the Eye"). They all (most notably One Million) resemble OMACs as much as Superboy. (This was a very intentional pun, as the title of the story was "One Million And Counting", referring to the million clones, and forming the OMAC acronym.)
- Justice Legion T: Members include Superboy (as referred to above), Robin the Toy Wonder (optimistic robot sidekick to Batman One Million) and Impulse (the living embodiment of random thoughts lost in the Speed Force). They are based on Young Justice.
- Justice Legion Z: ("Z" for Zoomorphs) Members include Proty One Million and Master Mind. They are based on the Legion of Super-Pets.
Equipment: None known.
Transportation: None known.
Weapons: None known.
- The Justice Legion does not have future counterparts of Green Lantern (nor even the existence of the Green Lantern Corps) and the Martian Manhunter; one reason for the nonexistence of a Green Lantern and to extent the Green Lantern Corps was revealed in Final Crisis: Legion of 3 Worlds, in which by the time of the 31st Century the Green Lantern Corps was defunct due to the demise of Green Lantern Mogo, who was responsible for distributing power rings to new ring-bearers; the Martian Manhunter had become one with the planet Mars and his role replaced by Resurrection Man.
- No trivia.