At the moment of his birth, Brainiac 5 experienced what would be his last truly happy memory before his Legion membership: his mother holding him, for what would be the first and only time, before she realised she didn't care about him, like everything else she had done. She summarily left Colu immediately afterward, and the scandal resulted in all records of her being purged.
From childhood onwards, he was forever impatient and superior, babysat by robots while politicians planned to use him to their own ends - robots which he would take apart to study. At night, bored by the Sleepnet, he would lie awake, thinking of the mother whose face he could not remember.
At the age of eleven, he would reach what the Coluans decided was the final straw - he was undertaking an unapproved energy experiment, when his overseers discovered this and intervened. Despite his warnings, they had their robot guards pull him away and attempted to shut it down, despite his warnings, leading to the death of one of them and the explosion of the experimenting chamber - albeit high above Colu after the survivor belatedly allowed him to shut it down as safely as he then could.
They then "donated" him to Brande Industries to be rid of him. Eight months, five laboratories and a seven-figure repair bill later, even R.J. Brande had to admit he couldn't afford him, and found him an internship at the Time Institute's training centre on Talus alongside Rond Vidar.
There, a few years later, he would receive his Legion draft notice - and promptly ignored it, slapping it into his mounting pile of unread correspondence. His absence was only noticed after Kid Quantum's death; and Brande needed to make at least two calls to him to finally have him report.
Even when "Brainy", as he would reluctantly be dubbed, had relocated to Legion Headquarters, he spent his first day there rewiring and reengineering his laboratory, ignoring his teammates to the point where Invisible Kid and Cosmic Boy believed he was a lab technician until Brande corrected them, and remained in the lab even when the team were sent on their next mission - to the Moon, to save Leland McCauley from Mano. However, he would still play a vital part in Mano's defeat; upon Live Wire's realisation that that they didn't know how Mano's power worked, Invisible Kid called him - who was at a crucial stage of an experiment at the time. Annoyed at this, Brainiac would reason that Mano was waiting until his power recharged to the point where he could destroy the moon with a touch, giving them 23 minutes and 42 seconds to stop him; spurring them to desperate measures to stop him, which they did just in time.
Soon after, the Legion would receive a call for another mission which Brainiac 5 was to take the lead on - to the Coluian engineered Planet Hell. After briefing his teammates on the planet, a prison held within a red giant star - and refusing off questions on why he was named after Brainiac (1), who still had an evil reputation, even in the 30th Century, they touched down on the planet. Eventually, despite Brainy's efforts, it was Lyle (Invisible Kid), who figured out how to save them after the temporary tunnel which had allowed them entry collapsed, despite Brainy's dismissal of the plan.
This professional rivalry would come into play again when Lyle discovered the result of his interruption of Brainy's experiment during the Mano case. Brainy had inadvertently created a floating metal because of the interruption, and was going to discard it when Lyle saw its potential - he used it to create the Legion flight rings, which allowed the Legionnaires to communicate with one another and to, of course, fly. This earned Lyle the admiration of his teammates - and further jealousy from Brainy.
However, Brainy's superior intellect would still serve the Legion many times, most notably by recreating his ancestor, Vril Dox II's anti-lead serum for Andromeda when she had been poisoned by the White Triangle for turning on them after they had disobeyed her by beating Triad-Neutral into a coma (Brainiac himself had saved her life after this). At first, Brainy refused to give it to her because he wanted her, with her Triangle-derived beliefs discovered, to admit his race was superior; when she wouldn't, he told her to look him in the eye and state that his race was inferior. After Andromeda couldn't say this, he gave her the serum.
Brainy's intellect would play a big role again when the White Triangle ravaged Earth. Brainy built a miniature stargate, and when Saturn Girl telepathically lured the Daxamites to Legion HQ, Brainy activated it just as Jan Arrah transmuted a rod to the tarnium needed to make the Stargate work. They had saved Earth from the Daxamites.
Their victory was marred, though, by Andromeda's supposed death. Brainy was heartbroken, as he had developed a crush on Andromeda. He started to seclude himself in his lab, despite Cosmic Boy's frequent summons. Unbeknownst to anyone, though, Brainy had developed a working time machine, which he used to visit Guy Gardner's bar in the 20th century. When Saturn Girl sensed Valor in the Phantom Zone, Brainy was able to contact him for a limited time, and learned that he had been sent there by Superboy in the 20th century. A group of Legionnaires then travelled there to enlist Superboy's aid in freeing Valor.
Brainy and Superboy did not get along well at all, and an insult by Brainy caused Superboy to attack him telekinetically. This caused Brainy to develop a forcefield belt for his own protection.
After Valor had been freed, Brainy sent Superboy back to the 20th century and tried to track XS down, since she had been lost in the timestream on their first trip. However, he himself was trapped when the villain Chronos destroyed the time machine. Despite Invisible Kid's efforts, the time machine was beyond repair.
He was saved when Brainy's old colleague Rond Vidar managed to tap into the timestream again, allowing him to partially manifest and communicate. With aid from Cosmic Boy, Saturn Girl and Lori Morning, they were able to push Chronos into Brainiac's image, merging him and Brainy. Brainy was then able to use Chronos' costume to send the villain back to the 20th century and return himself to the 30th. His freedom was short-lived, however, when Science Police sent by President Chu arrived to arrest him for unauthorized time travel.
Unknowingly, the development of the time machine also spurred Chu to destroy the Legion, as she was afraid they could use time travel to undo all her political machinations. This led directly to the Sun Eater hoax, the brainwashing of Jan Arrah, the framing of Winema Wazzo and the formation of the Fatal Five.
Brainy, though, did not really mind imprisonment, as this allowed him to think without any distractions. When the warden brought in renegade telepath Nara Minsork to retrieve the time travel secrets from Brainy's mind, she was bounced out by his superior mental control. She then used forbidden technology to empower herself and re-enter Brainy's mind, though this carried the risk of permanent mental shutdown to him. She found out that Brainy was motivated to build the time machine not to undo Andromeda's apparent death, but to see his mother's face again - a memory that Brainy had unknowingly suppressed. Brainy, though, sent Nara out of his mind again, without the knowledge she had gained.
When the Fatal Five attacked the Legion, Shrinking Violet went to borrow Brainy's forcefield belt so she could enter Tharok's body safely and shut him down. Brainy told her the belt was too complex for her to use, and deactivated his own cell by revealing that he had decipheed its security code! He saved Invisible Kid in battle, but his arrogance caused him to fall to the Persuader. When the Legion regrouped later, saved by a Rescue Squad - which included Andromeda - Brainy was part of the group which exposed President Chu to the whole United Planets. He would then be pardoned by R.J. Brande when Brande was drafted as president, and rejoin the Legion.
Andromeda, though, would decide to leave. When she told Brainy about her decision, knowing that he had a crush on her, she was stunned when all he said was that it was a good thing M'Onel could replace her powers, and stormed off angrily.
Brainy would later almost quit the Legion when he felt that they were relying almost entirely on his intellect, leaving him little time for his own pursuits. Only after a lot of talk and promises on Violet's part, including the hiring of Dr. Gym'll to act as physician, did he consent to staying. Out of gratitude for his increased lab time, he would build Violet a special present - only to find that the Emerald Eye had granted his fondest wish by making everybody around him unable to notice his presence!
Brainy was one of the Legionnaires who was stranded in the 20th century following the Emerald Eye's possession of Violet. He would be instrumental in coming up with the plan to save Earth from the Sun-Eater, but he would chafe at the lack of technology with which he could build a working time machine to return the team to the future. During this time, Brainy would also butt heads with Gates, but oddly enough, would start building friendships with Spark and, of all people, Impulse! He would also be adopted by Koko, a white lab monkey which the team accidentally freed from STAR Labs.
His greatest disaster, however, also came during this time after he freed his great-great-grandfather, the original Brainiac, from mental and physical confinement in STAR Labs. While - after Vril Dox II (Dox), his great-grandfather and the first Brainiac's son, intervened to help - they would stop his plans to take over Colu, a moratorium on technological development was put in place there as a result, which would lead to a millennium of stagnation on the planet, leaving Querl, as he confessed to Dox, devastated - and noting that even he himself rarely invented anything - something Dox challenged him to rectify.
Brainy would then put together a Legion Omnicom, a Metal Man responsometer and a Mother Box from the Gods of New Genesis to create C.O.M.P.U.T.O. ("Cybercerebral Overlapping Multi-Processor Universal Transceiver Operator"), a powerful living computer. C.O.M.P.U.T.O. would serve Brainy well at first, even creating a time portal for the Legion to return home with but a thought! However, when the Metal Men Iron and Platinum insisted that Brainy deactivate C.O.M.P.U.T.O. and return the responsometer, C.O.M.P.U.T.O. was angered by what it saw as abuse and attacked the Legion.
Brainy was able to come up with a plan to stop C.O.M.P.U.T.O., and with the help of the Justice League, Impulse, Superboy, Robin and the Legionnaires from the 30th century, they were successful and able to finally return home.
Shortly after their return, though, Brainy was part of the team which investigated a strange space-time Anomaly which M'Onel and Andromeda, now a nun, had disappeared into. There, Brainy was transformed physically and emotionally; his skin colour changed, his forcefield became internalized, and he became much more friendly and sociable! He even became good friends with Gates, who dubbed him Brainiac 5.1, which everyone would call him thereafter. However, this was threatened during the Dark Circle crisis.
During the crisis, Brainy returned to Colu and made peace with the Coluans by showing how he had matured, convincing them not to join the Affiliated Planets. In gratitude for this, the Coluans showed Brainy a picture of his mother, and even summoned him when she had returned to Colu! Brainy was looking forward to a happy reunion with her when she attempted to kill him, and he was saved only by the intervention of Gates, Spark and Live Wire. This trauma caused Brainy to withdraw into his former cold state, but Gates talked him out of it.
He would then throw himself into inventing, as Dox had earlier challenged him to do. In the course of a "productive week", he would invent the Anywhere Machine, a device that allowed its' user to view anything, appearing as a non-corporial image if desired; and a shrinking ray. Unfortunately, he would also experiment on Bizarro cells taken from Lexcorp during his 20th Century sojurn, which backfired and proceeded to "Bizarrofy" the whole Legion Outpost and those inside it. Only Invisible Kid and Bizarro-Koko's genius managed to set the situation to rights again.
During this time, he would also play a part in defeating Pernisus and helping Thunder reunite the Rock of Eternity despite his antipathy to magic. But magic would play a greater role in the return of the Emerald Eye as the new fifth member of the Fatal Five (replacing Mano). With the Outpost empty of all but him and Gates, they could do little more than escape, leaving the Outpost to the Five. Once the team regrouped after their sojurn to Summer World, however, the rest of the team kept all but Tharok busy, while Brainy and the powerless Magno defeated him and retook the Outpost. In the process, however, Koko grabbed his flight ring, found a mate and remained on the planet. He was devastated, but maintained that he was happy Koko was gone - though not a single one of his teammate failed to see through it.
Brainy was part of an away team, including Cosmic Boy, Apparition and Monstress, which had investigated a freighter hijacking in space. They found that it had been boarded by a robot who had come to retrieve the robots which had been used as ballast on the ship. Oddly enough, the robot had identified Brainy as a Brainiac and a "hated of Colu", and has tried to kill him. Brainy was left wondering how the robot could have known him.
He wouldn't be able to wonder long, though. The team found that the Stargate network had been shut down, and it took them a month to reach Earth. They returned to find it taken over by the Blight. The foursome regrouped with Chameleon, XS and Saturn Girl and were able to infiltrate the Blight's base and destroy them freeing Earth.
After the Great Rift Disaster, Brainiac 5.1 was one of the Legionnaires thrown through the Rift itself, and thus trapped in the Second Galaxy for a time.
During this time, he felt under great stress, as his teammates all believed he could devise a way of getting them home, in addition to all the other responsibilities forced upon him by their circumstances. As he eventually confessed to Saturn Girl however, he didn't have a clue how to get them home - or even where "home" was, relative to their location. In the same conversation, he also complained that he'd "always hated [his] name upgrade," and on the way out, as well as reassuring him, she made a point of redubbing him "Brainiac Five," and he dropped the ".1" from his name thereafter. Eventually, using his new teammate Shikaris tracking skills and an interdimensional doorway they'd earlier found but been forced to leave, he did get them home.
Brainy continued to be active in the Legion, providing Invisible Kid and Gear with the blueprints for the interdimensional doorway that had brought them home. This technology would be recreated and developed by the three on Legion World and called Threshold. He was also part of the team which rescued Gates and delayed Ra's al Ghul long enough for the other Legionnaires to stop his terraforming of the Moon.
Brainy nominated himself for Legion leader, and was noticeably miffed when he lost to Kid Quantum (Jazmin Cullen). He, Shvaughn Erin and Kinetix were trapped on Earth, though, when Robotica invaded, and he was captured to find that Robotica's leader was Computo! Computo, who had dropped the acronym from his name, had apparently been reactivated centuries ago, and had lived on the edge of the galaxy all this time, gathering robot life into an army to destroy all humans. Computo had gone to Earth to "hijack" the evolutionary process that Ra's al Ghul had started, and Brainy helped him to the dismay of his fellow Legionnaires. However, Brainy knew that Computo would become peaceful after it evolved, and so the Robotican threat was defused.
Powers and abilites
Brainiac 5 possesses a "twelfth-level" intellect, placing him well beyond double the intellect of humans. This manifests himself partially as twelve parallel thought-tracks, meaning he can concentrate on multiple topics at once, or bear an even greater level of intellect on a single problem.
After his "upgrade" by the Anomaly, his force-field apparatus was bonded to him, allowing him to control and shape it mentally.