So a while back, I reviewed “The Boy with the Ultra-Powers,” the first appearance of Jo Nah of Rimbor, later to be known as the Legionnaire called Ultra Boy. In that first appearance, in Superboy 98, Jo talked on and on about his Penetra-Vision, which allowed him to assist (and baffle) Superboy by seeing through lead. Superboy’s X-Ray vision couldn’t do that, so this was a pretty big deal.
The other Legionnaire who could out-see Superboy was Star Boy, who first appeared in “Lana Lang and the Legion of Super-Heroes” in Adventure Comics #282. In that story, Star Boy also had all of Superboy’s other powers.
Jerry Siegel and Curt Swan create another new Legionnaire, like Mon-El, not billed as such at the outset, and, like Mon-El, slated to be one of the power-houses of the Legion. In this issue, however, he has only the power of “Pentetra-Vision,” a power broader in scope than Superboy’s X-Ray vision. Eventually, he would be shown to have all of Superboy’s powers, but only to be able to use one of them at a time. (Ironically, Star Boy, in his first appearance, had all of Superboy’s powers as well. He would trade those for a single power. As of this issue, however, Star Boy had not appeared again.)
Ultra Boy comes to Smallville with his elder friend, Marla. They wear the same red and green “action costumes” (why Marla wears a version of Ultra Boy’s costume is never explained) and report via a “cosmic scope” to a secret headquarters. Their mission: to find Superboy so that Ultra Boy can discover his secret identity. Marla reminds Ultra Boy that he’s in trouble if he fails in his mission. Oooh, these guys seem like bad news!