Fighting for mutant rights can take on all kinds of meanings. Time and again, the X-Men are thrown into conflicts with mutant terrorists. After all, their message is one of peace, of co-existence between mutants and average humans.
Most of the villains they encounter tend to have the same basic principles on some level; they simply fight for mutant rights in a more extreme and aggressive manner. Because of this, it’s no surprise that several of the X-Men’s biggest enemies would wind up joining the team, at least for a little while.
Some of these characters joined the X-Men for a very brief time, some have done it a few times, some of them are even currently on one team or another. Other characters have joined the group in alternate timelines or mediums such as the films or cartoons—surprisingly, though, they’re in the minority.
In the mainstream continuity, after fifty-plus years of publication, the X-Men have proven to be very forgiving and accommodating toward their former foes, even if it has occasionally gotten them into trouble.
Here are the 15 Supervillains Who Joined The X-Men.
Magneto is the most obvious choice. Everyone who’s familiar with the X-Men at this point knows that Magneto is never an adversary to the team all the time.
However, he’s more than that. His views of mutant superiority are at odds with the X-Men’s views of peace, but he simply wants the best for his people. There are times, especially recently, when he’s lessened his drastic measures to try to play by the rules of his old, dear friend, Professor X.
Magneto’s first, most famous turn to the side of good was when he led the New Mutants for a time when Xavier was whisked away to the Shi’ar Empire by Lilandra.
He may have secretly joined the group under the guise of Xorn in Grant Morrison’s New X-Men, though there has been some debate as to whether or not that was really him. In recent years, he’s been a regular member of the group, having been a mainstay of Uncanny X-Men in some of its most recent incarnations.
There was a time when Sabretooth seemed like the least likely character to ever join the X-Men. Largely portrayed as a vicious psychopath, Sabretooth’s hatred of Wolverine runs so deep that one would think he’d reject any offer to join the team on principle alone.
Throughout most of his classic appearances, he never appeared to have much stake in mutant rights one way or the other. However, he was a Weapon X lab rat, same as Wolverine, and over time the grossly unethical experimentation he’d been subjected to began to eat at him in the same way. Of course, Sabretooth still worked with teams like X-Factor while he was a villain, albeit on a very short leash.
Recently, though, he was part of the main roster in Uncanny X-Men, alongside former villains such as Magneto and Mystique. Sabretooth has been siding with the forces of good more and more recently and has shown a genuine attempt to turn over a new leaf, even if it doesn’t always agree with him.
Deathbird is the jealous sister of Shi’ar Empress Lilandra. She wants the throne for herself, desperately. Despite her classically villainous motivations and attempts to usurp her sister’s rule, Deathbird has wound up allying herself with the X-Men on several occasions.
When allying with the X-Men to fight off a Phalanx invasion on the Shi’ar homeworld, Deathbird actually winds up forming a romantic relationship with the X-Man Bishop.
She attempts to keep on the side of good for a time, and when Bishop sees her let an enemy live instead of killing him, he begins to hope that he’s having a positive influence on her.
However, she ultimately betrays Bishop to the Skrulls in a deal made with Apocalypse, who then betrays her and turns her into his horseman, War. Since that incident, Deathbird has more or less remained a villain ever since.
Toad was never very good at being a villain. Even in the original Brotherhood, facing off against the very first, very inexperienced X-Men, he did not represent much of any kind of threat. He’s mostly been the mascot of whatever super-team he’s aligned himself with over time.
Naturally, the X-Men would take him in as one of their own. Toad was eventually recruited to work at the school, which by that point had been renamed the Jean Grey School For Higher Learning—as a janitor.
Though serving as a custodian has still made him the butt of some jokes, Toad has come into his own as a character and has shown serious attempt to prove himself as more than just a thug or hired gun.
Juggernaut was one of the X-Men’s earliest enemies. As the half-brother of Charles Xavier, he’s originally depicted as everything the professor isn’t: he’s all brawn and no brain. Over time he’s grown a little more complicated but has never strayed too far from his original characterization.
When he first joins the X-Men in the pages of Uncanny X-Men, it’s part of a plan hatched by his frequent partner in crime, Black Tom Cassidy, to destroy the team from within. But when Cassidy betrays him, Juggernaut elects to stay with the X-Men and make an attempt to change his ways.
Juggernaut also briefly joins New Excalibur for a time. Eventually, his attempts at reformation began resulting in a loss of power during World War Hulk. Only by returning to his old ways does he find the strength to restore his connection with the gem of Cyttorak that gives him his power. Confronting Xavier afterward, Juggernaut admits that reformation is ultimately impossible.
Avalanche is a mainstay member of the second Brotherhood of Evil Mutants, which is run by Mystique. This Brotherhood is notable for eventually turning into the government sanctioned Freedom Force. For time off their collective sentences, after all the damage they’d done as mutant terrorists, Mystique and her Brotherhood agreed to run shadow missions for the government. Avalanche was a part of that operation.
The animated series X-Men: Evolution has given the character the most spotlight, however. He’s shown to be the most responsible member of the Brotherhood in this version, even acting as almost a parent figure to the others. He also has a romantic connection with Kitty Pryde, eventually leading him to attempt to join the X-Men just so that he can be closer to her.
While Cyclops sees this as a scheme by the Brotherhood, Avalanche is serious in his attempt at reformation. But he leaves when it becomes clear that despite what they preach, the team cannot overlook his criminal past, and will blame him for everything that goes wrong if he stays.
Danger is a character that is sort of introduced by Joss Whedon during his now-iconic Astonishing X-Men run. During this series, it’s revealed that the Danger Room is actually sentient and that Professor X abandoned it when he realized it was alive— much like Frankenstein.
Through a series of holograms and the Danger Room’s heavy arsenal, the room attacks and disorients both the X-Men and the collective students. Forming a body for herself in the rough shape of a human, she calls herself Danger.
When teaming with Ord to defeat the X-Men on the Breakworld, Danger ultimately realizes that she hasn’t overcome her programming, that she really can’t kill any mutant, and sides with the X-Men in the fight.
After that, she still attempts to take her revenge on Xavier, but is stopped. She eventually joins X-Factor and serves as transportation for the original, time-displaced X-Men via the Blackbird jet.
Like Avalanche, Pyro is primarily known as a member of Mystique’s Brotherhood of Evil Mutants. However, Pyro has never really shown to have much of an interest in doing anything that evil. He’s always had a softer side, despite his fiery nature.
He’s even a bestselling author when he’s not a thief or, occasionally, a wanted mutant terrorist. He also serves with the Brotherhood when it is rebranded as the government shadow ops group Freedom Force. In the comics, Pyro was a victim of the Legacy Virus. Unlike most comic characters, his death appears to be permanent.
In the film series, Pyro is actually a student at the school, in training to be an X-Man alongside Rogue and Iceman, until Magneto opens his eyes to the Brotherhood and the path he’d rather take. In Ultimate X-Men, Pyro joins the X-Men for a time.
He’s shown to be a spy, but it’s actually part of a plan to trick Stryfe, a nod to his original version’s villainous nature. He’s later seen with the Brotherhood in Ultimatum, despite there being no inclination toward his desire to join that group or even leave the X-Men before that.
Many complain at Mystique’s redemption arc in the recent films, particularly X-Men: Apocalypse, but the character has a long history of changing sides. She’s done many villainous things, for sure, and that will always be a part of her nature. But Mystique cares about her people, first and foremost. Anyone who gets in the way of that is simply collateral damage in her eyes. She briefly works with the US government when her Brotherhood is rebranded as Freedom Force and also serves as a spy for Professor X himself in her own solo title.
Mystique first joins the X-Men when she infiltrates the group by posing as a young mutant named Foxx. She attempts to seduce Gambit simply to break him up with Rogue, but is eventually found out, at which point she declares her loneliness and desire to join the team. Mystique is granted membership on probationary status, though to the shock of no one, she ultimately proves herself to be a traitor.
In one of the most iconic and important X-Men stories of all time, Professor X recruits a new team of X-Men when the original team goes missing somewhere in the South Pacific.
This arc is when heavy-hitters such as Colossus, Nightcrawler, Storm, and Wolverine join the team. They eventually find the original X-Men on an island called Krakoa and are shocked to realize that the island is actually alive and keeping the mutants hostage. Even though Polaris launches Krakoa into space during that event, it’s revealed that several of its spores have remained behind.
Some of these spores grow to attack the X-Men, but others do not. It’s eventually revealed that Beast has built the Jean Grey School for Higher Learning on top of one of these spores. This latest incarnation of Krakoa essentially serves as the sentient school ground, proving itself to be the best home defense system imaginable.
Quicksilver should, in some ways, be one of the most obvious characters on this list. He did technically start out as a villain. All the way back in X-Men #4, he battles the team as a member of the first incarnation of the Brotherhood of Evil Mutants, alongside his sister, Scarlet Witch.
However, what is surprising is just how long it actually takes Quicksilver to join the X-Men. After reforming, both he and Scarlet Witch join the Avengers. Then, Quicksilver becomes a regular member of X-Factor.
In the films, though, he’s shown no hesitation with joining the team. In X-Men: Days of Future Past he’s briefly recruited to break Magneto out of prison, and in X-Men: Apocalypse, he joins the team to help break through to Magneto after learning that the master of magnetism is his father. At the end, he’s shown suiting up alongside perennial members such as Storm, Nightcrawler, Jean, and Cyclops.
4 Quentin Quire
Though Quire has always been depicted as a student at the Xavier Institute/Jean Grey School, his first appearance was pretty much as a terrorist. Showing utter contempt for the idea of humans existing peacefully with mutants, Quire tries to rally the students to demand justice for recently murdered mutant fashion designer Jumbo Carnation. With his group of friends, Quire attacks and kills a group of humans on the street.
When the school holds its open day for parents and media, Quire declares it “open season” on all humans, leading a violent riot. After the damage he’s done, Professor X puts him a stasis he refers to as a “higher plane of existence.”
His later attempts at revolution decay into simple teenage rebellion and he join’s Wolverine’s team in Wolverine & The X-Men.
Right-hand woman to the villain/inter-dimensional TV producer Mojo, Spiral has had a long history of conflict with the X-Men, serving as a longtime enemy of Longshot, Dazzler, and Psylocke in particular.
She has joined the Brotherhood of Evil Mutants and stayed with it when it became Freedom Force. She has even helped organize her own Sisterhood of Mutants. When Mojo takes away her ability to teleport between dimensions, Spiral joins up with X-Force.
Her Ultimate X-Men counterpart shows a much softer side. This version of Spiral is a love interest of Longshot’s, though their relationship is somewhat rocky. Spiral aids the X-Men briefly in this incarnation until they can help her emigrate to the US, so she can be with her sister, who is also a mutant.
In X-Men: The Animated Series, Spiral also betrays Mojo and aids the X-Men after falling in love with Longshot. Their relationship clearly doesn’t last, though, as she’s back by Mojo’s side in the villain’s second appearance.
When Wolverine puts a new team together in the pages of Uncanny X-Force to do the dirty work that the X-Men can’t, their first mission is to stop the apparent revival of their most powerful enemy, Apocalypse.
They fight through his horsemen only to come to a shocking reveal: Apocalypse has been reborn in the body of a child. He has no idea what he will grow up to become, but his very existence is a threat to the world. Fantomex shoots the child in cold blood, but eventually his guilt leads him to revive the boy.
Dubbing himself Evan Sabahnur, aka Genesis, the young incarnation of Apocalypse enrolls in the Jean Grey School for Higher Learning. There, it is hoped that an education in peaceful coexistence will prevent him ever growing up to become the powerful villain his previous incarnation was notorious for being. Evan later joins the time-displaced X-Men in the pages of All-New X-Men.
1 Emma Frost
Emma Frost, formerly the White Queen of the Hellfire Club, is introduced as a villain in one of the most iconic X-Men stories ever told: The Dark Phoenix Saga. She’s the best example of a villain-turned-X-Man because she’s equally known for being both.
After the deaths of her students, the Hellions, Emma makes an effort to redeem herself, eventually forming Generation X, alongside Banshee. Emma then became a member of the X-Men in Grant Morrison’s New X-Men.
Although Emma and Cyclops have a brief psychic affair while he is still married, the two eventually form a relationship after Jean’s death. Though the team often doesn’t trust her and her relationship with Cyclops is rocky, it becomes clear that she’s very serious about being an X-Man, even if she has her own way of leading and her own way of dealing with things.
She’s very different from Professor X, but is often shown to be perfectly able to dish out the blunt, tough love that the students—and even her teammates—often need in a crisis.
Can you think of any other supervillains who have joined the X-Men team that we forgot to mention? Let us know in the comments!