The X-Men get a bad reputation among Marvel teams for having a very complicated continuity. While there is some truth to that, the X-Men are no more or less complicated than the Avengers or Fantastic Four. That said, the X-Men have had a lot of retcons over the years. Some of them haven't been the best but others of them have helped the X-Men become one of the biggest names in comics for years.

RELATED: The 10 Smartest Characters From X-Men Comics

Retcons have become a great weapon in the arsenal of X-Men writers, allowing them to spruce things up from the past and modify it to fit their stories. This has helped the team grow in some amazing directions over the years.

8 The Death Of Professor X Was A Ruse

X-MEN DEATHS - Changeling from Marvel Comics

One of the first X-Men retcons came during the team's early days. Professor X was killed in battle only for it to be revealed that it wasn't Professor X at all, but Changeling. Changeling had agreed to take the Professor's place while he worked in the basement of the X-Mansion in a psi-proof chamber to help stop an alien invasion by the Z'Nox. The only member of the team who knew was Jean Grey.

It was a pretty big surprise to readers, as they couldn't figure out what direction things were going to take or why Changeling had taken Xavier's place. This early retcon would be the first of the many, as the X-Men became one of Marvel's more retconned franchises over the years.

7 X-Men: Deadly Genesis Showed How Shady Professor X Could Be

x-men-deadly-genesis

X-Men: Deadly Genesis, by writer Ed Brubaker and artist Trevor Hairsine, revealed a secret from the X-Men's past that changed the way readers looked at Professor X. When Krakoa took the original X-Men prisoner, the All-New, All-Different team wasn't the first team of mutants Xavier gathered to save his students.

RELATED: The 10 Strongest Characters From X-Men Comics

Instead, he used Moira MacTaggert's students Sway, Petra, Darwin, and Vulcan, along with Cyclops. This team was slaughtered by the mutant island, with Cyclops escaping back to Xavier. Xavier mindwiped everyone involved, which made things worse when it was revealed that Vulcan and Darwin had survived. Readers got a first hand look at the lengths Xavier would go to and were introduced to the Omega class mutant Vulcan and Darwin.

6 Cyclops' Role As Leader Wasn't Exactly Earned

Cyclops X-Men Jean Grey Polaris

Cyclops is one of Marvel's greatest team leaders and for years, people thought he got where he was because he had earned it. In Joss Whedon's Astonishing X-Men, readers learned different. It was revealed that instead of making Cyclops team leader because he was the best for the job, Xavier did it to stop the young man from committing suicide.

Xavier knew that Cyclops's low self esteem was his greatest weakness, so he made him leader to build him up. It worked perfectly. Cyclops believed that he had earned the role of leader of the X-Men and this made him feel better about himself. He used that to get better and better, becoming the X-Men's greatest leader and eventually taking over command of the mutant race during their most desperate hours.

5 The Many Retcons To Wolverine's Origin Made Him One Of The Team's Most Interesting Members

A giant Wolverine surrounded by helicopters - the variant of Wolverine #18

Wolverine is the best there is at what he does. Wolverine's man of mystery origin was a big part of his appeal, but fans wanted to know more about who he was and his origins. These reveals would set off a wave of retcons, as Marvel was afraid to define the character too much, lest he lose his mystique and popularity.

Marvel's writers would reveal things about Wolverine's origin and then later writers would walk them back. While this sometimes could make things rather confusing, it served to make Wolverine a much better character. He never really lost the mysterious aura that made him so captivating, but fans know enough about him to keep them guessing.

4 Making Gambit A Part Of The Mutant Massacre Added A Layer To His Origin

Gambit Discussing the team roster of The Marauders

Gambit became a fan favorite mutant but there were always secrets with him. He was much like Wolverine in that way, since he was created to take up some of the mystery slack from Wolverine as more and more started to be revealed about Wolverine's origins. There was always something sinister about Gambit, which would prove to be apropos when it was revealed that he had worked for Mister Sinister in the past.

Gambit specifically worked for Mister Sinister during the Mutant Massacre, leading the Marauders to the Morlocks in their sewer tunnels beneath Manhattan. This was a huge reveal about the Cajun mutant, paying off secrets revealed about him years before.

3 Xavier Gave Mister Sinister The Idea To Start His Mutant DNA Database

Mister Sinister from Powers of X

Mister Sinister's massacre of the Morlocks was one of his worst acts, but it completely fit into his eugenics based belief system. He saw the Morlocks as an evolutionary dead end, a belief he came to because of his database of mutant DNA. For years, Mister Sinister had collected the DNA of every mutant he could get his hands on. Everyone thought it was because of his desire for knowledge but the origins of it were retconned in Jonathan Hickman and R.B. Silva's Power Of X.

Xavier, Magneto, and Moira MacTaggert gave him the idea. Xavier used his mental powers to not only make Sinister forget it wasn't his idea, but that he would work with Xavier at some point in the future when asked to. In a lot of ways, Sinister's attack on the Morlocks was because of Xavier, as he never would have thought them evolutionary dead ends unless he was collecting mutant DNA.

2 Moira's Mutant Retcon Changed The X-Men Forever

The cover to Marvel Comics' X-Men Inferno Moira MacTaggert

Jonathan Hickman made a huge splash when he came to the X-Men and his biggest surprise came in House Of X #2. This comic revealed that long time human X-Men ally Moira MacTaggert was not a human at all. She was a mutant with a very important power: Moira was reborn after her death, getting to live her life all over again. This allowed her to try and change the world to her liking over her ten lives.

RELATED: 10 Strongest Villains The X-Men Beat In The Comics

Moira's lives were full of triumph and tragedies. In her present tenth life, she revealed the truth to Professor Xavier and then Magneto before the formation of the X-Men. The three of them worked together behind the scenes, laying the framework for the mutant nation of Krakoa. This retcon changed the X-Men's status quo forever.

1 The Return Of Jean Grey Brought Her Back After "The Dark Phoenix Saga"

Jean Grey's resurrection in Jamaica Bay in Uncanny X-Men #101

"The Dark Phoenix Saga" is one of the greatest X-Men stories of all time. Chronicling the fall of Jean Grey from Phoenix to Dark Phoenix, the comic ended with Jean killing herself in order to save the universe from her terrible appetites. "The Dark Phoenix Saga" didn't originally end this way, but Marvel editor in chief Jim Shooter decreed that Jean had to be punished for her actions in the story, which is why it ended with her dying.

Years later in Fantastic Four #286, it was revealed that Jean Grey had been alive the entire time, placed in a cocoon in Jamaica Bay by the Phoenix Force. Jean Grey was never the Phoenix at all; instead, the Phoenix Force became a simulacrum of her. This brought the fan favorite character back to life, putting her in many stories over the years.

NEXT: X-Men: Which Characters Would Most Likely Win In Squid Game