A 30th century youth named Jo Nah and a member of the Legion of Super-Heroes, Ultra Boy from the planet Rimbor eventually is revealed to have comparable powers to Superboy and Mon-El, though he can only use one super ability at a time. In his first appearance, he possesses Penetra-Vision - sight more powerful than Superboy or Mon-El as Ultra Boy can even see through Lead, but not the super-dense material known as Inertron.
As an adult, Jo marries long-time girlfriend, Phantom Woman (Tinya Wazzo).
An alternate version of Ultra Boy is encountered by Superboy when the Boy of Steel is hurled to a different reality after an alien sun goes nova. Upon his arrival in the parallel (and mis-spelled) "Smallvile", Superboy meets the counterparts of five members of the Legion of Super-Heroes: Brainiac 5, Chameleon Boy, Element Lad, Invisible Kid, and Ultra Boy - who in this universe are evil. During this encounter, the five delinquents attempt to expose Superboy's secret identity as Clark Kent. Superboy, after realizing what they are up to and that he is in fact on a parallel Earth, is able to contact his counterpart, who has been away on a mission. The two Superboys assist each other in thwarting the criminals' efforts and, after apprehending them, return the villainous Legionnaires to their own time (SB No. 117, Dec 1964: "Superboy and the 5 Legion Traitors").