Brainiac 5 (real name: Querl Dox) is a member of the Legion of Super-Heroes in 30th Century Metropolis (Act No. 276/2, May 1961: "The Three Super Girl-Friends"; and others). Possessed of a 12th level intelligence common to his homeworld of Colu, his many inventions have included the Legionnaires' time-traveling bubble, the best cure for Mon-El's lead poisoning, flying belts, flight rings, and Computo.
Both Supergirl and Brainiac 5 apply for Legion membership at the same time but Supergirl is rejected as Red Kryptonite has turned her into a "Superwoman" and over the 21-year age limit for membership (Act No. 276/2, May 1961: "The Three Super Girl-Friends").
As depicted in the chronicles repeatedly, Brainiac 5 and Supergirl are sweet on each other. (TGSB)
Note: the original future time-frame of the Legion of Super-Heroes is chronicled as the late twenty-first century, hence only four generations separated Brainiac 5 from his namesake "ancestor." The bulk of the Legion stories are firmly placed in the 30th century, and the character's name is unchanged.
A member of the Legion of Super-Heroes. A green-skinned humanoid alien from the planet Colu (also referred to as the planet Yod), Brainiac 5 possesses an extraordinary superhuman intellect that enables him to perform intricate calculations in seconds, gives him a strong resistance to hypnotism, and has made him a super-scientific genius of incredible creativity, ingenuity, and inventiveness. Long believed to be a descendant of the space villain Brainiac, Brainiac 5 is actually a descendant of Vril Dox, a Colutian boy who led his people in the successful overthrow of the computer tyrants which had seized controf of Colu and created the humanoid computer Brainiac as the first step in a scheme of interplanetary conquest.
Brainiac 5â€™s real name is Querl Dox.
In April 1962, Brainiac 5 is among the six Legionnaires who play an elaborate hoax on Superman and Supergirl as a prelude to celebrating the anniversary of Supergirlâ€™s arrival on Earth (S No. 152/1: â€œThe Robot Master!â€).
In October 1962, when Superman is believed to be dying from exposure to Virus X, a malady fatal to natives of the planet Krypton, Brainiac 5 labors desperately to find a cure for the virus before the Man of Steel succumbs completely. Brainiac 5â€™s dedicated effort ends in failure, but Superman regains his health when it is discovered that his symptoms are actually the result of exposure to Kryptonite and the kryptonite fragment responsible is hurriedly removed from his presence (S No. 156: â€œThe Last Days of Superman!â€ pts. I-IIIâ€”â€Supermanâ€™s Death Sentence!â€; â€œThe Super-Comrades of All Time!â€; â€œSupermanâ€™s Last Day of Life!â€).
In February 1963, Brainiac 5 frees Mon-El from his self-imposed exile in the Phantom Zone after successfully devising a serum capable of curing Mon-El of his potentially fatal vulnerability to lead (Adv No. 305: â€œThe Secret of the Mystery Legionnaire!â€).
In February 1964, while probing the universe with his â€œtime-space thought-scannerâ€ in the hope of locating an ally capable of helping him destroy Superman, Lex Luthor learns that the space villain Brainiac is not a being of flesh and blood at all, but a humanoid computer, and that Brainiac 5 is not his descendant, but rather the descendant of a youngster whom Brainiacâ€™s creators had chosen from among the population they tyrannized with the intention of forcing the boy to aid them in carrying out their scheme of interplanetary espionage by posing as Brainiacâ€™s son (S No. 167: â€œThe Team of Luthor and Brainiac!â€ pts. I-IIIâ€”â€The Deadly Duo!â€; â€œThe Downfall of Superman!â€; â€œThe Hour of Kandorâ€™s Vengeance!â€) (TGSB)
An alternate version of Brainiac 5 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: Chameleon Boy, Element Lad, Invisible Kid, Ultra Boy, and Brainiac 5 - 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").