Bullied by classmates, Guido Carosella’s mutant powers manifest, bulking up his body when he becomes furious. He works as singer Lila Cheney’s bodyguard but helps Alison Blaire, AKA Dazzler, with her career after Lila disappears. Naming himself Strong Guy, Dazzler convinces him to join X-Factor, and later, the X-Factor Investigation agency.
Bullied to Bodyguard
Class clown Guido Carosella uses humor to overcome his own insecurity as a self-confessed nerd and social outcast. Developing a crush on fellow student Sheila McCann, the teenage Guido tries to speak to her, but her boyfriend punches him, and the boyfriend’s buddies gang up on Guido when he retaliates. The beating triggers Guido’s mutant powers, causing his right arm to swell. In pain and confusion, Guido stumbles in front of a school bus, absorbing further energy when it strikes him, expanding his physique even more. As Guido collapses in agony, Charlie Ronalds, whose parents had been killed by a mutant, tries to smash Guido’s skull with a rock; but Guido spasms, striking Charlie and permanently crippling him. Unaware of the need to discharge his excess energy quickly, Guido is permanently disfigured, his upper body disproportionately super-sized and in constant pain. Recovering, Guido becomes close to candy-striper Mary Bradley, but loses touch with her after being transferred to another hospital. After his parents are killed by a falling satellite, Guido becomes wealthy from the settlement, moving in with his aunt and uncle until he reaches the age of maturity.
When bad investments leave him tight for cash, Guido works as a bodyguard to mutant rock star and interstellar thief Lila Cheney. During this period, he meets members of the X-Men, including Dazzler, then one of Lila’s session singers; later finding Alison amnesiac near Lila’s Malibu home after she had passed through the Siege Perilous, Guido takes her in while she recovers.
Soon after, he accompanies Lila to the X-Men’s Westchester Mansion, but when she departs with some X-Men for Shi’ar space to rescue the team’s founder, Professor Charles Xavier, AKA Professor X, Guido falls under the Shadow King’s telepathic sway. Drawn to Muir Island, Scotland, Guido joins a gladiatorial arena alongside other pawns including Theresa Cassidy, AKA Siryn, Lorna Dane, AKA Polaris, and Jamie Madrox, AKA Multiple Man, though the X-Men eventually free them all. Immediately after the battle, Guido, Polaris, and Madrox are recruited by federal official Valerie Cooper to form part of the new government-run X-Factor. They are soon joined by Alex Summers, AKA Havok, Pietro Maximoff, AKA Quicksilver, and Rahne Sinclair, AKA Wolfsbane. At the team press launch, Guido is pressed to choose a code name, and on the spur of the moment, he picks Strong Guy.
Designated Strong Guy
Guido absorbs kinetic energy on impact, using it to increase his mass and strength; he must discharge excess energy within 90 seconds or risk permanent physical deformation. Thanks to the energy he absorbed and did not quickly discharge when he discovered his powers, Guido's baseline strength enables him to optimally lift 50 tons. The upper limit to his absorption power is determined by the rest of his body’s ability to handle the energy; absorbing several large amounts in short order previously strained his heart, but he now has a surgical implant to strengthen this organ, presumably raising his limit, and when highly charged he has lifted well in excess of 100 tons. He is nearsighted. He is skilled in street-fighting techniques, and a talented musical comedy actor and stand-up comedian.
X-Teams and Mutant Malcontents
Guido is a reliable and fierce friend to his X-Factor and X-Factor Investigations teammates. He’s closest to fellow X-Factor mate Multiple Man and will sacrifice himself for the X-Men’s ideals. He also harbors a candle for Monet St. Croix, AKA M, who doesn’t return his feelings but remains a colleague nonetheless. Working with various X-teams over the years, Guido battles many x-enemies, such as the mind-manipulating Shadow King, Nathaniel Essex, AKA Mister Sinister, the Brotherhood of Mutants, and other super-strong mutants like Fred Dukes, AKA Blob.
When Guido loses his soul, his personality changes for the worse. He ends up committing murder and such as sin leads him to become King of Hell. Although, he gives up the throne when a battle with Thunderbolts member General Thaddeus Ross, AKA Red Hulk, changes his tune to recover his lost soul and atone for his misdeeds.
Going Strong
X-Factor, the fledgling team, soon battled Mister Sinister and his Nasty Boys. One of them, Slab, took hostages at the Washington Monument and challenged Guido; during the battle Slab dodged a punch, and Guido accidentally demolished the Monument. Humiliated and briefly arrested, Guido considered quitting X-Factor, but soon redeemed himself, defeating Slab during their rematch and helping X-Factor expose Sinister’s plan to deliberately discredit them.
X-Factor next stopped the Brotherhood of Evil Mutants from recruiting Genoshan refugees, the X-Patriots, with Guido growing particularly close to one, Jo Beth, AKA Pirouette, while guarding her. Following an assassination attempt on X-Men founder Professor X, X-Factor joined several other X-teams to hunt the shooter, Stryfe (Nathan Summers, AKA Cable’s clone). Subsequently defending the X-Patriots from the mercenary Marshall Evan Stone III, AKA Random, X-Factor then escorted them home to Genosha, where Guido bid farewell to Jo Beth.
When the team learned of the lethal Legacy virus’ spread, they battled Genoshan Magistrates trying to kill an infected mutant. After returning to the USA, X-Factor fought Charlie Ronalds, AKA Charon, who had sold his soul to the demonic Cloot, AKA Satannish, to seek revenge on Guido and all mutants; the battle ended when Cloot decided Charon had broken their bargain and claimed him.
Lila Cheney later tried to rehire Guido as her bodyguard, but feeling that his friends needed him, Guido declined. While X-Factor was trying to apprehend the new-age mutant healer and cultist Radha Dastoor, AKA Haven, Guido learned that his closest friend Madrox was dying of the Legacy virus, only minutes before he died. Unaware that one of the self-replicating Jamie’s bodies had survived (though it remains uncertain whether the original Madrox or a duplicate had passed away), Guido was hit hard by his friend’s seeming demise. Following Jamie’s funeral, Guido visited his family in Rhinebeck, accompanied by Wolfsbane. He received a warm welcome from most of the residents as one of the town’s favored sons, complete with his own fan club, and unexpectedly encountered his old crush Mary Bradley (now Vanderbilt); however, Guido’s newly lifted spirits came crashing down when Mary shamefacedly admitted she considered him a freak after he confessed he still loved her.
Departing in haste, he raced with the rest of the team to Hawaii to assist Havok and Polaris, who had been attacked by the Nasty Boys and the psychic entity Alice MacAllister, AKA Malice. Attending one of Lila’s concerts, Guido had a chance encounter with Blob at Dulles International; during the ensuing battle Guido absorbed large amounts of kinetic energy from the Blob’s punches, from a high fall, and finally from catching a jumbo jet. Overloading, Guido suffered a minor heart attack, though he put the pain down to indigestion, and still captured the Blob before his teammates arrived. X-Factor was sent to Tel Aviv to protect Professor Xavier’s son, David Haller, AKA Legion, from mutant shape-shifter Raven Darkhölme, AKA Mystique, only to have him teleport them to Madripoor, where Guido was taken prisoner by Jornik, an alien seeking Lila Cheney who recognized Guido from his time working for her. Lila freed him, but X-Factor was attacked by the K’lanti, seeking to recover a Harmonium Lila stole. Lila teleported herself, Polaris and Guido to Cygnus Prime to retrieve the Harmonium, where Guido absorbed large quantities of kinetic energy fighting a robotic guardian before they returned to Earth with the device. The departing K’lanti left behind a bomb, and Guido interposed himself between it and Lila, taking the blast head on. Unable to handle the excess energy, Guido had a heart attack and collapsed. Comatose, he was admitted to the Hidalgo Research Institute in Washington, suspended in amniotic fluid to give his heart muscles a chance to heal away from external pressures.
He awoke months later to learn his friend Madrox was alive but a fugitive, as was Havok, now leading an outlaw mutant Brotherhood; his heart still dangerously weak, Guido was placed into custody in case the Brotherhood tried to recruit him, but Madrox freed him. As government troops closed in, Guido tried to use his strength, but began experiencing chest pains again; rescued by Polaris, Guido was given a heart implant by mutant inventor Forge that directed kinetic energy to the organ, ensuring it grew in proportion with his other muscles, thus preventing further health problems.
Guido vacationed for a while with Lila, who convinced him to go on a new intergalactic tour, during which both the Jorken and Kront races tried to use Guido as a hostage to force her to use her teleportation powers as a weapon in a territorial war over a small moon. Unfortunately for both incompetent species, they kidnapped the wrong person. After Guido tricked them into destroying the disputed moon, they allied intending to take revenge on both Guido and Lila. Later informed of a radio signal mentioning an impending alien invasion of Earth, unaware it was Orson Welles’ 1930s broadcast passing out into deep space, Guido returned home. Allied with Hank McCoy, AKA Beast, and old friends Madrox and Wolfsbane to find the nonexistent invasion, Guido instead stumbled upon Melvin J. Weals’ plan to open an underworld portal using the Hell Toupee and sacrifice a former romantic interest to demons; Guido ultimately donned the flaming wig and ordered the demons back to the pit empty-handed, before departing for space once more.
Returning to Earth after an undisclosed falling out with Lila, Guido sought a new focus, becoming a fighter in Masato Koga’s underground Arena. He ended up indentured to Koga until the X-Men’s Ororo Munroe, AKA Storm, Japanese adventurer Yukio, and former Morlock leader Callisto helped him win freedom for all of the fighters. Taking up residence in New York’s Mutant Town district, Guido worked for Madrox’s XXX Investigations, soon joined by Wolfsbane; at Guido’s suggestion, they renamed the agency X-Factor Investigations.
After “M-Day,” when a mad Wanda Maximoff, AKA Scarlet Witch, depowered most of the world’s mutants, Guido was one of the few who retained his. An expanded X-Factor, with new members M (Monet St. Croix), Siryn, Layla Miller and the depowered Julio Richter, AKA Rictor, investigated M-Day’s cause while defending mutants, both powered and depowered, from enemies who sought to exploit the situation. Aware of a future where X-Factor reversed M-Day, leading to mutants brutally dominating the world, the temporal anomaly Mr. Damian Tryp and his Singularity Investigations worked against them; Tryp brainwashed Guido and had him murder Professor Henry Buchanan. After Singularity was destroyed, Guido was deprogrammed, though he became guilt-ridden upon learning he had committed murder; however, when he confessed to Buchanan’s widow, she forgave him, not wishing Singularity to claim another victim.
When X-Factor defended Xavier’s school against an attacking Bruce Banner, AKA the Hulk, Guido suffered another minor heart attack after absorbing too much energy fighting him. He briefly considered leaving X-Factor when Val Cooper offered to make him the “sheriff” of Mutant Town, but she withdrew the offer as the area’s falling population rendered the post moot. Soon afterwards the assassin Arcade burned down Mutant Town, and X-Factor relocated to Detroit to avoid being drafted into government service by Cooper, though she soon tracked them down.
Siryn, pregnant by Madrox, gave birth, but her son proved to be an unusual kind of duplicate which Jamie accidentally absorbed; an enraged Siryn drove Madrox away. After he had been missing for a month, Rictor located a Madrox duplicate, John Maddox, in New England. Hoping he might provide information on Madrox’s whereabouts, Guido and Rictor visited him, but were attacked by Gaveedra-Seven, AKA Shatterstar, Rictor’s former X-Force teammate, now mind-controlled by Cortex, a Jamie Madrox from 80 years in the future of Earth-1191, an agent of Mr. Tryp. When Cortex’s control was disrupted and this freed Shatterstar, he passionately kissed Rictor. Guido was shocked, partly because he had not suspected Rictor’s bisexuality, but also because the proudly open-minded Guido found himself having difficulty accepting this revelation. The trio swiftly returned to Detroit to aid the rest of X-Factor in their battle with Cortex.
Guido also helped his X-Factor teammate M with finding her kidnapped father, and began to develop romantic feelings for her, though she did not feel the same way. While searching for her father, they ran into Baron Karl Mordo, AKA Baron Mordo, and forces led by Dr. Bolivar Trask, leading them to flee into a nearby temple where they found her father. There, they learned Mordo’s intentions with kidnapping her father: he intended to use M’s energy to free him of cancer. The forces that worked against them outside threatened the stability of the temple so M tricked Mordo into helping them escape and then turned her telepathy on him, tricking into thinking his cancer was gone. Later, Guido eventually shared his feelings with M but it was after he suffered a fatal shot from assassin Ballistique and he was crushed by a Mandroid during an ensuing battle. He perished from his injuries and despite Layla Miller resurrecting him with her powers, his body was restored but not his soul.
This new soulless Guido began exhibiting a different personality—he became more aggressive and lacked empathy. He went on a date with M but it wasn’t what he expected, and in his rage, he quit the team afterward. He began working for Hell-Lord Mephisto, helping him with the throne of Hell, but once M died, he took Hell’s throne for himself, slaying Wolfbane’s son Tier Sinclair, all to revive M. When the Thunderbolts were stuck in Hell, they worked with Mephisto, who still desired the throne, and therefore T-Bolts member Red Hulk fought Guido for it. He ultimately convinced Guido to give it up and reunite with his soul. This change of heart allowed Mephisto to regain the throne, while Guido searched for his lost soul.
Guido was eventually reunited with his soul thanks to Ilyana Rasputin, AKA Magik. He worked with the X-Men and fellow mutants against the Inhumans and joined the New Mutants team where he came face to face with former teammate Wolfsbane since he had murdered her son. Guido apologized for his part and then had a heart attack. Magik saved him by allowing him to be infected with the techno-organic virus. However, Magik’s team was then imprisoned by the government and experimented upon, infecting all of them, so they could weaponized mutants for their own ends. When Wolverine and Scott Summers, AKA Cyclops, faced a reluctant Sentinel who begged them to stop attacking them, they open up the Sentinel’s hood to discover Guido, who like the others on Magik’s team, had been integrated into the destructive robots. They then liberated the rest of the team from the other Sentinels as well as all the nearby imprisoned mutants. When they were all together and ready to head out, one of Multiple Man’s duplicates exploded—the government having placed a bomb inside him to account for any attempted escapes. Guido absorbed the majority of the blast with his powers but died from it. The mutants had to leave him behind to save themselves and his body was kept in the custody of General Callahan, an enemy of the X-Men.
Once the independent, mutant-only island nation of Krakoa came to be, Strong Guy returned from his death, most likely having been resurrected by the Five whose purpose was to bring back all fallen mutants, no matter their previous standing on the hero or villain spectrum.