Juggernaut has been one of the X-Men’s most powerful enemies over the years thanks to his vast superhuman strength, invulnerable body, and unstoppable nature. Few X-Men can match him in sheer physical power, requiring the team to employ unconventional strategies in taking him down. Fortunately, Juggernaut is also not the smartest guy in the room, allowing keener opponents to take out his mind control-shielded helmet, and let his stepbrother Charles Xavier hit him with a paralyzing mental blast.

But what if this wasn’t the case? What if Juggernaut was both the strongest and the smartest villain in the Marvel Universe? Surprisingly, this happened in one universe when Charles Xavier, not his step brother Cain Marko, wound up getting the power of the Juggernaut.

Related: Wonder Woman Beat Marvel’s Juggernaut With ONE Punch

Weird as it might sound to have someone like Professor Xavier become an unstoppable behemoth, it actually almost happened in the mainstream Marvel Universe! In Juggernaut’s original comic book origin, both he and Charles Xavier served in the Korean War. While trying to hide from all the fighting, Marko accidentally found the lost temple of Cyttorak and discovered the Crimson Gem of Cyttorak. Xavier followed him and watched Marko touch the gem and became the Juggernaut, only to be caught in a rockslide that took him years to dig his way out of. Xavier, meanwhile, escaped, had several more adventures, and ultimately founded the X-Men.

Iron Man Hulkbuster Juggernaut Cover

In the alternate universe presented in What If --? #13, however, Xavier – not Marko – accidentally touched the gem first. As a result, Xavier became the Juggernaut but was caught in the cave-in. By the time Xavier managed to use the power of the Juggernaut to dig his way out, Magneto was attempting to conquer the world without the X-Men to oppose him. The Fantastic Four managed to oppose him, but anti-mutant hysteria rose dramatically thanks to Magneto’s crimes.

Meanwhile, Xavier’s telepathic powers allowed him to stay aware of what was happening outside of his prison, but he was unable to interfere in what happened. By the time he regained his freedom, his sanity was gone, causing him to emerge with a single-minded purpose – to make the world safe for mutants at any cost. This involved going to the United Nations and letting them know that all mutants are now under his protection and that he will move against any human attempting to harm any mutant.

Related: Thor Beat Juggernaut By ‘Giving’ Him His Hammer

Xavier then confronts Magneto – who had created a safe haven for mutants in order to establish his own mutant army – and tells him he is not the right man to lead mutant kind. Magneto attempts to attack the Juggernaut, but with the limitless power under Xavier’s command, his power proves useless. Furious, but knowing he’s outmatched, Magneto departs the Earth.

Without Magneto to challenge him, Xavier turns his attention to the Fantastic Four. By using his telepathic abilities, he looks into the minds of not only Reed Richards but also Doctor Doom, Bruce Banner, and other great scientists and uses their combined intelligence to concoct a gas that removes superhuman powers. With the Fantastic Four depowered, Juggernaut orders them to leave. The gas also ends up “curing” the Hulk, removing the one being who might be able to challenge the Juggernaut physically.

Xavier’s telepathic abilities and limitless physical power also allow him to take out Earth’s other defenders. He bankrupts Tony Stark, driving him to alcoholism and rendering Iron Man ineffective. He threatens to expose Peter Parker’s secret identity, preventing Spider-Man from interfering in mutant affairs. He even shrinks Giant-Man and the Wasp to microscopic size, re-freezes Captain America, and straight-up murders Doctor Doom.

However, while Juggernaut may have removed all the superhuman combatants from the playing field, humanity itself refused to submit to his rule. The Kremlin launched a nuclear strike, starting World War III… which lasted the better part of an hour as mankind basically exterminated itself with multiple atomic bombs, irradiating the Earth and killing millions of people.

Amid this devastation, the Juggernaut found a way to leech off the dangerous radiation from the planet, rendering it livable. However, the remaining radiation still affected the human survivors, giving rise to an unprecedented number of mutant births. Over the next several years, mutants end up becoming almost half the world’s population, turning them into a master race.

Although Xavier promised the world he would not be a dictator, he still showed extreme favoritism to mutants – giving them better access to housing and food. As a result, ordinary humans became second class citizens that were openly terrorized by mutants, including the Juggernaut’s fascist police version of the X-Men. Thanks to his telepathic abilities – now augmented by a version of Cerebro in the Chrysler Building, Xavier was able to root out any potential uprisings by listening to people’s thoughts and send his X-Men to issue an early strike.

Thor vs Juggernaut Comic Fight

But not all of the X-Men are willing to follow Xavier blindly. Angry that his team has basically degenerated into a group of bullies, Scott Summers (aka Cyclops) decides to leave the X-Men and ends up taking several other disillusioned mutants with him. They’re found by Cain Marko, of all people, who takes them to a version of Magneto’s outer space headquarters, Asteroid M. Convincing the renegade X-Men that the Juggernaut needs to be destroyed, Magneto outfits them with headbands that block Xavier’s telepathic abilities.

Related: Hulk Is Strong Enough To Beat Juggernaut With ONE Hit

Using these new tools, the X-Men attack their own base and lure the Juggernaut onto Asteroid M. Although Cyclops tries to convince Xavier that he’s just succeeded in fostering fear and not peace, Jean Grey and Quicksilver blow up the floor beneath him, jettisoning the Juggernaut into outer space. And although his superhuman body can survive in the depths of space, without any way to direct his flight, the Juggernaut will drift in the vacuum forever.

In the aftermath, Magneto decides to conquer the planet in the Juggernaut’s absence, but Scott and the remaining X-Men promise to stand against him and protect both humans and mutants from tyrants like him. It’s a grim ending that reminds readers of Xavier’s manipulative side, which ends up taking over his entire personality once he becomes corrupted by the power of the Juggernaut.

Next: Juggernaut Easily Stopped One of Marvel’s Most Explosive Mutants