DC Database

Jo Nah aka Ultra Boy from the planet Rimbor is a member of the Legion of Super-Heroes possessing a multitude of powers. However, due to physical limitations, he is only capable of using one of these powers at a time. He is romantically involved with fellow Legionnaire Apparition.

A freak accident irradiated Ultra Boy with a hyperkinetic energy bouncing inside of him that could be used for various effects.

He comes from the rough and tumble planet Rimbor, where he can never return to, or he'll be executed for a crime that, according to Triplicate Girl, he never committed.

Ultra Boy has dated Light Lass and Triplicate Girl earlier. He's currently dating Shadow Lass. Despite his ability to fly he shows a strong love of automotive transport; getting a good deal of pleasure from driving a (presumably incredibly antique) Car.

When Ultra Boy's powers began to go out of control, Shadow Lass forced him to seek help from Karate Kid.In a battle later in the same arc however, while Karate Kid and Ultra Boy are battling numerous foes Karate Kid questions why Ultra Boy isn't using the full extent of his powers. Ultra Boy responds that he is just following the Kid's teaching and Karate Kid; as they are being overwhelmed veritably orders Ultra Boy to stop trying to control himself and cut loose. Implying that his habit of rapidly switching between powers and not worrying was the key to managing them.


  • Ultra-Energy Empowerment: Ultra Boy can utilize the ultra-energy in his body in a variety of ways, but only one at a time. He can utilize it for any of the following:
    • Ultra-Strength: When Ultra Boy uses this power he is many times stronger than usual.
    • Superhuman Stamina: Ultra Boy could sustain prolonged physical exertion without tiring or undo strain for an indeterminate period of time.
    • Superhuman Speed: Ultra Boy could run at a velocity many times greater than that of a normal human being. Unlike other super-speedsters however, Jo Nah's "Ultra-Speed" is not rooted in the Speed Field, and thus he has no physical connection to the Speed Force.
    • Super-Breath: Ultra Boy possessed the ability to create hurricane force winds by blowing, and to chill an his breath in order to freeze a target. This ability has also been referred to as "Ultra-Breath". Ultra Boy could also breathe in large amounts of air, an ability used when dealing with and disposing things like clouds of poison gas.
    • Ultra-Invulnerability: When using this power, he is impervious to harm by nuclear forces. If propelled at sufficient force, by either his flight ring or a super-toss, Ultra Boy can use his ultra-hard body like a human missile.
    • Flight: Ultra Boy could fly by psionically manipulating a planet's gravitonic field. Although he did not require the use of a Legion Flight Ring, he still wore one in recognition of his commitment as a Legionnaire.
    • Ultra-Vision: Ultra Boy's penetra-vision makes him able to see through solid matter, although he appears to be unable to see through lead. As part of his same ultra-vision power, Ultra Boy can use telescopic vision, in combination with penetra-vision if desired. He also has microscopic-vision and is able to analyze fingerprints.
    • Energy Projection: Another vision-based power, Ultra Boy could project beams of concentrated thermal energy from his eyes, which he referred to as "Flash Vision". Flash vision works along the same properties as Superman's Heat Vision.



  • One Power at A Time: As mentioned above, one serious limitation to his ultra-powers is that he can only use one at a time. This means that if he wants to fly through space at super-speed he must wear a spacesuit to survive in the cold vacuum. When using his power for super-strength he is not invulnerable and can therefore get tired, feel muscular pain or even pull a muscle.
    While he can switch his ultra-energy from one power to another almost instantaneously, Ultra Boy can be caught off-guard and unawares.
  • Penetra-Vision Limitation: Ultra Boy's penetra-vision appears unable to penetrate lead.




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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".
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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, Prime Legion and the Post-Rebirth Legion.
This template will categorize articles that include it into the "Legion of Super-Heroes members" category.