Professor Charles Xavier is the long-time leader of the X-Men, a (mostly) noble group of super powered mutants who fight evil in an effort to save humanity — often from other mutants, who think humans need to become extinct. Despite Prof. X’s position as “boss of the good guys,” there have been a number of times in his character history that Charles has acted… well, pretty bad.

Xavier’s mutant power is all in his head, as he has one of the most powerful minds in human history. He is capable of mind reading, mind control, and memory manipulation. His brain is easily one of the most powerful weapons in the entire Marvel universe. If he’s not completely in control of those powers, or has a major lapse in judgement, Professor X is actually capable of some pretty awful things, ranging from mostly harmless to extremely deadly.

We combed through Xavier’s comic book and movie history, and came up with these 15 times that Professor X was anything but the good guy.

15. He Cheated in School. And in Sports

Having the ability to read the minds of everyone else is both a very useful and very dangerous ability. Long before he became the wheelchair-bound Professor X, he was just regular old teenage Charles Xavier — with one obvious exception. As a high schooler, he had already developed his psychic powers and started using them for very selfish purposes.

Not only would he read his teachers’ mind to cheat on tests and exams, he also became the star of the football team by using his abilities to correctly predict what the opponent would do on the field. He didn’t feel guilty about of his ill-gotten accomplishments, either. In fact, he devoted a whole section of his room to his trophies. He only retired from amateur athletics because he claimed it was far too easy for a mutant to beat normal humans. Basically, he got bored.

Via Marvel Comics

14. His Brain Was Used By Red Skull For World Domination

At the end of the Avengers vs. X-Men story arc, Cyclops actually kills Professor X (it’s a long story). But if you thought that Xavier’s powerful and dangerous mind was finally out of commission for good, you were dead wrong. In Uncanny Avengers #1, the Red Skull actually steals Xavier’s brain and attempts to use it to destroy all mutants and take over the world.

Red Skull uses X’s brain to control Scarlet Witch, who can warm reality into a state where mutants don’t exist. When that doesn’t work, he uses Xavier’s psychic abilities to incite an anti-mutant riot in Manhattan and gets Thor to turn on his Avengers teammates. When Captain America eventually thwarts his plans, the Red Skull uses Charles’ brain to transform into the Red Onslaught and start “World War Hate.” Okay, we know all this happened after Xavier was already dead. And it’s not reeeaaaaaaalllly his fault. But Charles never fails to disappoint.

Via Marvel Comics

13. He Constantly Endangers Children

Let’s face facts here, people. Charles Xavier runs a school for “gifted” children. And even though the X-Mansion doesn’t have a bunch of toddlers running around, the vast majority of students there are in the 13-to-18 age range. And for some reason, Professor X keeps thinking it’s a great idea to send these kids out for extremely dangerous missions against very deadly super villains.

Even when some of the teenage X-Men get older and become adults, Charles just recruits another batch of child soldiers to fight his battles. If a rich, middle-aged genius was recruiting kids to go off to war anywhere else in the world, people would be outraged. But apparently if you slap on the “X-Men” label, it’s perfectly fine. The crazy thing is that Charles’ mind is so powerful, he barely even needs a group of angsty teens to go throw punches.

Via Marvel Comics

12. He Traumatized His Own Students by Faking His Own Death

Although the X-Men are regularly tasked with saving the world, it’s important to remember that many of them are still students at the same time. After all, the X-Mansion isn’t officially named the Xavier Institute for Higher Learning for nothing. These kids go through regular schooling, as well as “special” courses that help them develop and control their powers. In short, there are still tests that need passing.

In X-Men #4, Professor X “loses” his powers and almost gets the X-Men killed by the Brotherhood of Evil Mutants. Later, he reveals that he never really lost them — he just wanted to test his students (and, ya know, totally endanger their lives). To make matters worse, Xavier actually “dies” in X-Men #42 (it was actually a shape-shifter names Changeling) and then the real Prof. X lets the X-Men all thing he’s really dead — for two full years! He didn’t even apologize when he finally revealed that he’d been alive all along!

Via Marvel Comics

11. He’s Kind of Responsible For Dark Phoenix

Professor X claims that he will accept whatever differences or powers young mutants have, and teach them how to control those abilities. However, that’s not always the case. When a young Jean Grey came to the X-Mansion, Charles immediately could detect that her mind was just as powerful as his, and maybe even stronger. In particular, he could sense Jean’s Dark Phoenix side and knew how destructive it could be. So rather than teach her how to control it, be meddled with her brain and attempted to lock away those parts of her mind.

It didn’t work, obviously. Dark Phoenix would eventually rear her powerful head and lay waste to mutants, humans, and almost the entire world. And of course, the end of Dark Phoenix also meant the death of Jean Grey herself. If only Professor X had been patient enough to coach Jean through the most troubling parts of her mind.

Via Marvel Comics

10. He Brainwashed Wolverine

Wolverine has been an X-Men fan favorite since the character was first introduced. Although he’s always been an outsider and a bit of a rebel when it comes to the rules, he forms a genuine respect for Charles Xavier, as Professor X constantly attempts to give Logan answers about his past, a home, and even a family to call his own. However, that friendship didn’t always exist. Wolverine isn’t exactly the most trusting person, after all. And it turns out that his instincts were basically right.

In Wolverine Origins #29, it’s revealed that Wolverine was originally sent to assassinate Xavier as a member of the secret Weapon X experiments. Xavier, obviously able to read Wolverine’s mind, sees the attack coming and thwarts it by brainwashing the aggressive Canadian into becoming a member of the X-Men. He removed a bunch of old memories, implanted some new ones, and basically left Wolverine’s brain a confused mess. But Xavier managed to get what he wanted — a powerful weapon to fight for his cause.

Via Marvel Comics

9. He Tried To Kill His Unborn Twin Sister

Charles Xavier was dipping into morally ambiguous things before he was even born. You see, Charles actually had a twin sister in the womb. But even unborn fetus Charles was already developing strong mental mutant abilities, and sensed that his twin sister would grow up to be evil. He forced her out of the womb, and the twin (who was to be named Cassandra) was declared a miscarriage. Charles was born and would inherit the vast Xavier fortune.

Cassandra, with strong mutant abilities similar to her brothers’, refused to die though. She spent over 20 years living in the sewers, slowly building a new body for herself in order to strike back at Charles. Cassandra managed to use Sentinals to destroy the island of Genosha, killing 16 million mutants in the process.

Via Marvel Comics

8 He Got a Bunch of X-Men Killed (and Lied About It)

In Giant-Size X-Men #1, Charles Xavier has to put together a brand new X-Men team. The reason? His original group is being held capture by Krakoa the Living Island. However, we later learn that this new team is actually the minor leaguers, because Professor X already sent a new squad of X-Men to save his original team — only to see them all horribly killed.

Rather than admit his poor decision making got a bunch of mutants killed in action, Charles simply erases the memory from everyone’s mind. Poof! Like it never happened. One mutant managed to survive that first failed attempt, though. It was Gabriel aka Vulcan, who happens to be the younger brother of Cyclops (Scott Summers) and Havok (Alex Summers). Rather than have them find out the truth, Xavier erases all memory of the youngest Summer sibling in the mind of Scott and Alex. When Vulcan miraculously returns from a space coma (yes, a space coma), it naturally creates a lot of problems and a huge rift between Cyclops and Professor X.

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7. He Was a Really Bad Dad

David Haller is a mentally broken and socially unstable person. He also happens to be one of the most powerful mutants to ever exist, capable of warping reality, manipulating matter, telepathic abilities, telekinesis, creating and controlling fire, splitting into multiple personalities, and time travel. That’s a lot of skills! He also happens to be the forgotten son of Charles Xavier.

Haller, more commonly known by codename Legion, was the result of an affair between Charles and Gabrielle Haller, who was one of the Professor’s patients. That bit of unethical behavior aside, David grew up never knowing his father and was severely traumatized during a terrorist attack when he was young. The attack manifested Legion’s powers into multiple personalities. A mentor like Professor X, who could teach David to control his powers and use them for good, is exactly what Legion needed. Instead, Charles only discovers the truth about his son after he has already caused numerous catastrophes, killing thousands.

Via Marvel Comics

6. He Enslaved a Sentient Being as a Training Exercise

Originally, the X-Mansion has a special training wing known as the Danger Room. It was a super fancy obstacle course, designed to test the X-Men’s abilities and prepare them for real life battles. After the room was destroyed, Xavier decided to add in a bunch of upgrades to the rebuild. Enlisting the help of a mutant named Forge, the Danger Room was injected with alien technology from the Shi’ar race, turning it into more of holodeck simulator than a fancy set of monkey bars.

Unfortunately, the new technology also happened to be alive. That’s right, the entire room became a sentient being. Xavier learned the truth via his mental abilities, but decided not to inform the rest of the X-Men. Instead he used the new and improved Danger Room as a personal training slave for his students. The Room eventually rebelled, convincing a student to commit suicide and trapping the X-Men inside after learning all of their weaknesses. A young mutant named Kitty Pryde eventually convinced Danger Room not to hurt anyone, and the Room actually became an important X-Men ally after that. Still, enslaving living beings is not a good look. Even when the being happens to be a room in your house.

Via Marvel Comics

5. He Cripples Mystique’s Self-Esteem

In X-Men: First Class, we see James McAvoy play a younger Charles Xavier who develops a deep friendship with Mystique, another mutant whose entire skin has turned blue but is able to shape-shift into any other form she has seen or touched. Oddly enough, Professor X urges Mystique to hide her “true self” in order to appear more human — in this case, the attractive blonde appearance of Jennifer Lawrence. We know that he’s probably only saying that in order to keep humans from panicking when they see Mystique, but it comes off as pretty insulting.

When Mystique meets Magneto later in the film, he encourages her to appear naturally in her blue form. It’s hardly a surprise when she falls for his “humans will kill all mutants” propaganda. After all, Magneto is the first person in her life to truly accept everything about her.

Via Marvel/Fox

4. He Totally Creeped on a Teenage Jean Grey

Jean Grey has caught the eye of many potential partners, most notable Scott Summers aka Cyclops and Logan aka Wolverine, as those two X-Men have famously competed for Dr. Grey’s affection in both the comics and the movies. However, when her character was first introduced way back in 1963, comic writers included a strange panel in  X-Men #3 that showed that a middle-aged Professor X was lusting over his new teenage pupil.

Xavier would go on to mentor Grey personally, as her powers are very closely aligned with his own. And the comics never really mentioned this plot point again, which hopefully means they came to their senses about having a 40-something grown man and school teacher fall in love with a buxom teenage redhead — even one with cool mutant powers.

Via Marvel Comics

3. He Murdered, Well, Almost Everyone as Onslaught

This one isn’t entirely Xavier’s fault, but the result was still pretty awful, so we’re including it anyway. Hang on to your hats, because things get pretty dark. For starters, Magneto used his powers to violently yank all of the metal out Wolverine’s bones. In response, Professor X used his powers to majorly mess with Magneto’s brain, putting him into a coma. Somehow, a piece of Magneto’s mind became stuck in Xavier’s. The two mixed together to form Onslaught, which separates itself from Charles and builds himself a surrogate body.

As Onslaught attempts to take over the world, almost every Marvel hero team comes in to stop him. The X-Men, Fantastic Four, and the Avengers all engage in an epic battle with Onslaught and his army of Sentinels. Most of the heroes end up dead, with some of the X-Men and Spider-Man managing to survive. Of course, since this is a comic book, it was later revealed that they weren’t really dead, just in another dimension. Onslaught may have ended up a separate being than Professor X, but we’re still pinning at least part of the blame on him for this incident. If he hadn’t gone messing around with Magneto’s brain, it never would have happened.

Via Marvel Comics

2. Let’s Not Forget About Logan

Most of the entries on this list are comic book related, which makes sense since the film versions of Professor X have been much more black and white than shades of grey when it comes to good and evil. By the time 2017’s Logan starts, it’s immediately obvious that something very, very bad has happened. The audience quickly concludes that the very, very bad thing was probably Xavier’s fault.

As Xavier ages, his brain starts to malfunction. Call it a sort of mutant Alzheimer Disease. He is prone to intense seizures that cause his powerful brain to destroy almost everything around him, including people. Only Wolverine is around to administer medication to stop the seizures. But the movie makes several mentions to “Westchester Incident,”  which is presumed to be a massive brain seizure that resulted in the death of the X-Men (and possibly many innocent humans as well). Westchester County is where the X-Mansion is located, after all. The scene is never actually shown in the movie, but Xavier’s guilt is written all over his face (thanks to a final, incredible performance by Patrick Stewart).

Via Marvel/Fox

1. He Created “How To Kill” Guides For All His Students

Batman isn’t the only one who famously gathered information and materials in order to defeat his friends, just in case one of them decided to suddenly switch sides. Professor X knew that the X-Men, many of whom were current or former students of his, possessed great powers that could be used for both good or evil. So he created the “Xavier Protocols,” a series of instructions on how to kill every single X-Men, quickly and efficiently.

Jean Grey, Xavier’s most prized student, said it best when she lamented: “Every night, when Charles went to his study to work, he was thinking of ways to kill the X-Men.” As expected, the Xavier Protocols fall into the wrong hands on numerous occasions, putting every X-Man in grave danger. They have managed to prevail though. So far.

Via Marvel Comics