Cosmic Boy is presently starring in the ongoing Legion of Superheroes series since the rebooted DC universe in the new 52. The Legion is presently fighting a Daxamite and a group of Controllers on the planet of Panoptes.
His parents struggling for work on the impoverished, metallic world of Braal, Rokk Krinn left at the age of 15 for the mother world of Earth to find work to assist his family. Following his flight, Krinn helped save billionaire R.J. Brande from an assassination attempt along with Garth Ranzz and Imra Ardeen. Brande was impressed by the youth and offered them work founding a team of young super-heroes. Rokk accepted and became Cosmic Boy, the team's first leader.
Cosmic Boy was created by Otto Binder and Al Plastino
During his tenure as leader the Legion's first year, he took the team from a trio of nobodies to an 18-member team of intergalactic heroes. Saturn Girl was elected his replacement. He served with the Legion for years, dedicated and being a figurehead as a founding member and the first leader even when just another active member. During his early years with the team, a romance blossomed between he and Legion of Substitute Heroes member Night Girl and Cosmic Boy made enough money to move his family to Earth.
Years later, a firebomb went off in the neighborhood where Rokk's parents lived. His whole family was hospitalized and his mother later died. This led Cosmic Boy to almost violate the Legion code of killing when he found the bombers, but he spared them. This event also encouraged his younger brother, Pol, to join the Legion Academy as Magnetic Kid. When he agreed with his fellow founders that they were getting old and it was time they resigned so the Legion got new blood, Cosmic Boy was pushing for his brother to be elected to the team in his place. Magnetic Kid became his replacement and Cosmic Boy enjoyed life as a reservist with Night Girl, traveling to the 20th century for a vacation. He would go on to found a second Legion of Substitute-Heroes with Night Girl and the Legion Academy instructors and mourned his brother when he sacrificed himself during the Magic Wars.
Five Years Later
During the Five Years Later after the Magic Wars, Cosmic Boy married Night Girl. His homeworld of Braal went to war with Imsk and he enlisted, alongside several childhood friends and former Legionnaires. At the battle of Venado Bay, Cosmic Boy was caught in an explosion that cost him his magnetic powers and left him disoriented. He stumbled into an Imsk camp thinking it was a Braalian one and would have been killed if not for Shrinking Violet stopping her troops. The disoriented Rokk, realizing now where he was, lashed out at Vi and left her scarred over one eye. He was never aware that it was Vi he had done that too until years later. Once the war was over, Cosmic Boy returned to the battered world of Braal. Lydda became pregnant and he found a chance to take his young family off-world when Reep Daggle implored him to help him re-found the Legion. The Krinns traveled to the Winath Plantation to make this happen.
Five Years Later / Batch SW6
A younger version of Rokk was found with several other young Legionnaires, called Batch SW6. Originally believing themselves just to be clones. It was later revealed that Val was time-paradox duplicates of his older counterpart self. The younger Cosmic Boy had the same magnetic powers and superb leadership abilities. He was named to lead the New Earth team of Legionnaires just as he had the original team. He was badly injured by a stray bolt from Live Wire, and was still recuperating, leaving vice-chairperson Computo in charge. The SW6 Cosmic Boy was one of few Legionnaires to notice when the "crisis in time" took hold. He, Saturn Girl and Live Wire traveled into the past to investigate their origins and wound up fighting alongside the 20th century's heroes during that "Zero Hour." They returned to the 30th century believing they had stopped the menace, but soon learned that they must reemerge with their older counterparts in order to repair the time stream. In true heroic fashion, Rokk joined hands with his older counterpart, and his best friends (both versions) and bid their reality farewell.
Reboot / Earth-247
Rokk Krinn's magnetic skills were discovered early and he became Braal's greatest and youngest professional Magno Ball player. This enabled him to support his poor family. Rokk's fans gave him the nickname "Cosmic Boy." While on a promotional tour, Rokk, along with Imra Ardeen and Garth Ranzz , prevented the assassination of interplanetary entrepreneur R.J. Brande. Impressed by the teens' bravery, R.J. convinced them to form the Legion of Super-Heroes. Rokk used Cosmic Boy as his codename and was unofficially the team's first leader. The government eventually tried to replace him with Leviathan, but Leviathan saw Cos was the better man for the job and stepped down. He served as team leader the Legion's first year and was instrumental in revealing President Chu to be a traitor to the United Planets. He called for a leadership election soon after and Shrinking Violet was his replacement.
Threeboot / Earth-Prime
Cosmic Boy was once again a founder of the Legion of Super-Heroes though this time the movement was more about youth rights and rebellion. His past was unknown, though his family still existed on Braal and seemed complacent with Rokk's involvement with the Legion. As the team's first leader, Cosmic Boy often had to appease the United Planets while also spreading their movement to gather more Legionnaire fans and supporters. Several Legionnaires became loyal to Cos' hardwork while others began to be persuaded by Brainiac 5, who thought he could do a better job. Eventually, the two sides came to blows until the leaders came to an agreement. Cos' homeworld of Braal was about to undergo quarantine and ordered all natives to return within 24 hours. Cos begrudgingly left the team, but ultimately returned at the last moment to save the day. Brainiac 5 relented leadership.
Retroboot / New Earth
Infinite Crisis restored the original Legion continuity, from before the Five Years Later. Cosmic Boy had rejoined the team following the Magic Wars and during the crisis of Earth-Man's Justice League taking over Earth became the leader again. He was captured at the Batcave with the other founders but ultimately released. At some point, Cos ended his relationship with Night Girl so that he could concentrate solely on the Legion and take care of the team so others, like the married Ranzzes, wouldn't have to worry. Cos, as leader, continued to deal with politics following Earth's bout of xenophobia and the Titanian refugees after Titan was destroyed. The pressure reminded Cos how much he disliked the politics of being Legion leader and he posted a call for a new leader election.
Post-Flashpoint / Earth 0
Following the conclusion of Flashpoint, the various timelines were united and rebooted once again. The Legion's timeline changed slightly where they still reached out to a young Clark Kent long before he became Superman, but they Legion grew up along with Clark and have changed their names to reflect their age. Imra changed her name to Saturn Woman and her along with Lighting Lad (Now Lightning Man) and Saturn Girl (Now Saturn Woman) reunited with an adult Clark Kent in an effort to stop the Anti-Superman army from destroying the original rocket that took Clark to Earth. They succeeded in saving the rocket and keeping he timeline intact.
Major Story Arcs
The Great Darkness Saga
Cosmic Boy leads a squad of Legionnaires consisting of Wildfire, Superboy, Phantom Girl and the newest Invisible Kid. Once they arrive their attacked by their shadowy foes who continues talking about the coming darkness while casually battling the assembled squad before retreating with the wand. Cosmic Boy then gathers his squad and races to London to prevent the ancient sword Excalibur from being stolen but Cosic Boy alongside Phantom Girl and Superboy are sent flying as Invisible Kid and Wildfire fail to prevent the newest shadow minion's escape with the sword. The squad then scrambles to prevent the theft of an ancient orb, but they fail but manage to capture one of "The Masters" shadow servants. Following several missions by three teams of Legionnaires Cosmic Boy calls to the worried Saturn Girl, but is attacked mid-call causing Saturn Girl to rush to his aid to find the captured servant to be the attacker.After a short battle however the two are defeated and only saved by Lightning Lad's arrival knocking out the monster.
Cosmic Boy alongside Saturn Girl and Lightning Lad are the Legionnaires to discover the identities of three of the shadow servants being Lydea Mallor, Superman and a Guardian of the Universe. Learning this prompts Cosmic Boy to send out a general alert to all Legionnaires. Cosmic Boy then takes part in the battle against the Daxamites under the control of Darkseid, being part of the team to distract him as Element Lad added lead into the atmosphere to activate their vulnerability. He later joins his teammates in an effort to capture the weakened Darkseid, but they fail as he flees. However following Darkseid's defeat he suffers another loss as a terrorist detonates a bomb in the city doing much damage, including to Cosmic Boy's home forcing his entire family to be hospitalized and leading to the death of his mother.
Cosmic Boy was visiting the now newly retired Lightning Lad, Saturn Girl and his god son Graym. It just happened to be the weekend in which the Legion's greatest foe attacked kidnapping Graym and delivering the challenge that only the three Legionnaires can battle him this time or he the child dies. Cosmic Boy then prepares to aid in the rescue of his godson visiting Metropolis University to request a leave of absence from coaching the Mangaball team. The three then head to Legion ally, Rond Vidar explaining the situation in confidence to gain a time machine but refuses prompting Saturn Girl to incapacitate him. Cosmic Boy then uses a distorter to assume the appearance of Rond leading them to a time cube as an officer attempts to stop them forcing Cosmic Boy to use his powers on him as he alongside his two friends activate the time cube.
The three then arrive at the the end of time, with the Time Trapper personally allowing a gap in the time barrier so the three can enter. The three then begin to battle the Trapper's minions in their efforts to kill the Legionnaires,but are captured by the surprise his minions are human bombs which releases nerve gas knocking them out and bringing them to his stronghold.Lightning Lad is then separated as Saturn Girl and Cosmic Boy escape battling Trapper's minions through out the citadel and gaining his aide Otok as a guide. He leads the two to Graym as they realize that he is well taken care of that Lightning Lad has been the true target. However the hour glass runs out before the Time Trapper can break Lightning Lad's sanity, as a result he sends all of them home to a point just shortly after they left.
Five Years Later:
The New Time Trapper
Cosmic Boy was the easy choice when the team reformed to lead again. Even though he was powerless, the other Legionnaires looked to him. Cosmic Boy and the Legion helped free Earth from the Dominators and saved Earth's populace when the planet exploded. A younger counterpart of Cosmic Boy, as well as the Legion from their early years, were discovered and went on to become the Legionnaires of New Earth. Brainiac 5 eventually created gauntlets for Cosmic Boy that would replicate his powers; however they slowly modified his personality and drove him mad. Shrinking Violet stepped in as leader. Going by Polestar now, he left the team to single-handedly rebuild Earth. He was subdued, but then captured by Glorith and Mordru during the Legion's last hours before Zero Hour. The whole Legion, past and present, rallied to save Rokk. and he managed to escape, but was lost in a library where time past differently. For hundreds of years, he lived in this library and studied the art of time manipulation. He ended up becoming the Legion's oldest foe, the Time Trapper. The Time Trapper freed his past self just as reality was coming to an end. Cosmic Boy merged with his SW6 counterpart, alongside the other Legion founders, as the last beings in the universe in order to reset time.
Reboot / Earth-247:
Trapped In The 20th Century
While Legionnaires like XS harbored a crush on Cosmic Boy, his eyes were set on Saturn Girl despite her fondness for Live Wire. She was his heart's desire and after an explosion left he and Imra stranded in the 20th century, the two began a romance much to the ire of Garth's sister, Spark. he enjoyed spending time with the heroes of legend he had grown up with during the team's exile. Cosmic Boy was left mentally comatose after Imra's mind was attacked by Dr. Psycho while he was linked, though he was ultimately revived by Saturn Girl's heightened powers. Unfortunately, she had just been subconsciously manipulating his body. Once she realized this, he was revived properly and in shame Imra ended their relationship and admitted she still had feelings for Garth. He hid his hurt and resolved to reunite Garth and Imra, which he did when their team returned to the 30th century.
The New Wanderers
Following the Blight invasion of Earth and half the team being thought for dead, the Legion was disbanded. Cosmic Boy secretly served R.J. Brande as a mercenary Legionnaire while Brande prepared Legion World and the reformation of a new Legion. When the Legionnaires thought lost returned and the team reformed, Cos became defacto leader. He helped end Ra's al Ghul's reign as secret president of the United Planets before calling for a new leader. Impressed by Kid Quantum II during the Ra's battle, he nominated her as his replacement and the Legion voted her in. After the incident, the two began a flirtation that became a romance. When Superboy was a member of the team, Cos rode him hard because he felt Kon wasn't living up to the legacy of Superman. Eventually, Earth-247 was destroyed and Cos and his Legionnaires were spared because they were lost in the timestream. After assisting two other Legions in defeating Superboy-Prime, he and Kid Quantum led their Legion into the multiverse to become the new Wanderers.
Threeboot / Earth-Prime:
Cosmic Boy Leaves The Team
When Supergirl joined the team, he was instrumental in helping her realize she wasn't dreaming and the two had a brief romance. Cosmic Boy was captured and tortured by Dominators, but it was all part of a plan to trick them into going to a wrong location. Cosmic Boy's last and most controversial move as leader was ordering the dying Mon-El to take a bomb to the heart of the Dominator planet and destroy it. In actuality, the bomb was a phantom zone projector that locked the Dominators away from Earth. Cos kept this a secret from even his close friends to prevent anyone freeing them. Sending a noble hero to his "death" as well as exterminating an entire race was poorly received by the Legionnaires and the public alike. A public leader election for the Legion was called and Supergirl replaced him. A trio of heroes from the Knights Tempus of the 41st century then appeared to Cosmic Boy. They told him that he was regarded in history as one of the greatest heroes ever and they invited him to join their team. Cos accepted and left the Legion. He never returned, though his war crimes were eventually pinned on Lightning Lord.
Powers and Abilities
Cosmic Boy's superpower is super-magnetism. He can manipulate, repel or attract metal objects of varying sizes. Naturally, the more metal is in an object the easier it is for him to affect magnetically. Cosmic Boy has been show to pull large iron meteors and satellites down from space with minimal effort. He can use his magnetic power on rocks that contain iron ore to pull or use them a projectiles. He can also magnetize metal objects so that they become magnets themselves and stick make them stick to other metal objects. His power cannot affect non-magnetic metals, such as aluminum and gold, or organic substances like wood or flesh. His control is such that he can manipulate electronic records or the iron in blood. He has been known to use a uniform with ferrous fibers so he can fly with his own powers, but usually relies on a Legion flight ring.
Legion Flight Ring
As a member of the Legion of Super-Heroes, Cosmic Boy possesses a Legion Flight Ring. The ring gives its wearer the ability to fly, the speed and range of which is determined by the wearer's willpower. It also acts as a long-range communicator (enabling constant vocal contact with other Legionnaires, even across vast distances of space), a signal device, and a navigational compass, all powered by a micro-computer built inside the ring.
Superman: The Animated Series
Cosmic Boy was one of three Legionnaires who traveled to the 20th century to stop Brainiac from altering time in the episode "New Kids in Town." He appeared to be the leader yet again and was voiced by Chad Lowe.
Justice League Unlimited
Following the same continuity as the Superman cartoon, Cos was still a Legionnaire but had been possessed by the Emerald Eye alongside much of his team in the episode "Far From Home." He was later freed and welcomed Supergirl into their ranks. He had no speaking lines.
Superman & The Legion of Super-Heroes
Cosmic Boy was a frequent supporting character in the two seasons of the Legion cartoon. Only name-dropped in the first episode, he made a cameo in the second before making regular speaking appearances at the end of the first season, starting with "Chain of Command." This Cosmic Boy was a Legion founder and the first leader of the team as well. He was overprotective of Saturn Girl, which caused he and Lightning Lad to clash. When a re-election was called, Cos expected to win again but was a good sport when the title randomly went to Bouncing Boy. He was one of many Legionnaires who assembled the Fatal Five and stood against the Sun-Eater in "Sundown."
During the second season, two years had passed and Cos is once again leader. He was injured in battle against the Legion of Super-Villains in "Man From the Edge of Tomorrow" but quickly recovered. He led a hunt against Timber Wolf in "Cry Wolf" when Wolf was suspected of violating Legion code. He protested Karate Kid's membership and fought Grimbor in "Karate Kid" and joined with his fellow founders in saving R.J. Brande in "In the Beginning." He rallied the Legionnaires and made a stand against Khund cyborgs and Brainiac with the team in "Dark Victory." Throughout the two seasons of the show, he was voiced by Wil Wheaton.
Cosmic Boy appeared in the live-action Smallville television show, portrayed by Ryan Kennedy. Alongside the other founding Legionnaires, they traveled to 21st century Smallville to stop Brainiac in the episode "Legion." The Legionnaires had planned to kill Brainiac's host, Chloe, but Clark taught them the value of never going down that road. When they are able to capture Brainiac without killing, Cosmic Boy resolved that the Legion would take up a code against killing. Cosmic Boy later returned to Smallville in the episode "Doomsday" to warn Clark against confronting Doomsday, as history showed Clark will be killed by him. He gave Clark a special flight ring and encouraged him to send Doomsday to the 31st century, where the Legion was in full force and waiting for him.