Origin of the Legion of Super-Heroes and Cosmic Boy is unknown, other than that he was the leader of the Legion, and that he founded it with Lightning Lad and Saturn Girl.

Dominator War

As the Wanderers have trapped most of the Legion in their headquarters with force-fields, Brainiac 5 decides to release Mon-El from the Phantom Zone, and manipulate him to fight Supergirl to shatter the force-fields, but without telling her. As far as Mon-El is released and begins fight with Kara, Cosmic Boy understands Brainy's plan. Brainy creates an antitoxin to Mon-El for Daxamite lead poisoning, and leaves it to the rest of the Legion to make Mon-El swallow it. Thanks to Atom Girl and Invisible Kid, Mon-El does, and comes to his senses, but is soon teleported of by the Wanderers. Cosmic Boy does later confront the Wanderers, who's leader turns out to be Mekt Ranzz, the brother of Lightning Lad (Garth Ranzz) and Light Lass (Ayla Ranzz). Mekt tells the Legion about the coming Dominator invasion, and Cos sends Brainy, Supergirl, Ultra Boy and Mon-El to Megatokyo, where the Dominators began with the invasion. The Dominators seem to have taken control of the Earth's technology in total, even the Legion's flight rings. After a failed rescue of some of Earth's residents, Cosmic Boy was captured by the Dominators. They tortured Cos to make him reveal the place of a rendezvous of the Legion and the Wanderers. He didn't say anything, but Triplicate Girl revealed it when they began to torture her. The Dominators did realise it was a trap, but that realisation was too late, since the Legion and the Wanderers had already gone trough the portal from Dominion to Earth, and begun a rampage on Dominion. After the final battle, the Legion and the Wanderers rested a little on a moon or a planet close to Dominion.
Cos had plans about sending Dominion to the Phantom Zone with a "bomb" that Brainy would build, and that had to be handcarried by Mon-El to the core of Dominion, but didn't know how to say that to the rest of the teams, with the thought of that Mekt Ranzz would probably try to retrieve Mon-El himself without any thought of retrieving something else too. Dream Boy solved that problem by telling them all that Cos planned to blow up Dominion with a bomb that Brainy was going to build. They discussed a while about who was going to deliver the bomb, but Cos decided that Mon-El was the one who was going to deliver it, since he would probably not survive anyway due to lead poisoning. Mon-El agreed, and delivered the "bomb". An election for the new Legion leader was held afterwards, and Supergirl won. However, before he could hear of the results, he had been contacted by the Knights Tempus (a crimefighting organization from the 41st century) and been asked to join them, and he accepted without telling anyone about it, leading to the Legionnaires next mission: finding him.




  • Gravity Negation: Sometimes when Cosmic Boy uses his powers (usually on a high degree), he loses control over his own gravity, and might require help from Light Lass or Star Boy to stabilize him.[3]




Legion Flight Rings
This character is exclusive to the continuity of the Supergirl and the Legion of Super-Heroes and 5th Legion of Super-Heroes series.

Any official designation for the home universe for this character has not been given, and thus this page may have to be moved in the future.
In the meantime, it's conjecturally designated as "New Earth".

Legion of Super-Heroes II 07
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Legion of Super-Heroes member
This character is or was a member of the Legion of Super-Heroes from the 30th/31st Century, in any one of their various continuities. Including but not limited to, Original Legion, the Reboot Legion, and the Prime Legion.
This template will categorize articles that include it into the "Legion of Super-Heroes members" category.

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