The MCU’s third phase is winding down, with Avengers 4 being the closing chapter. What comes after that is anyone’s guess, but it will certainly be something different. We know that Marvel and Disney will continue to make movies, but which movies they’ll make, and which storylines they’ll adapt, is anyone’s guess at this point. First and foremost on many fans’ minds is the recent news that Disney acquired Fox and regained the movie rights to a large portion of their comic characters, including characters associated with the X-Men and Fantastic Four. As the X-Men have had several successful movies from Fox, everyone is wondering what happens now that Marvel's mutants can show up in future Disney/Marvel movies.

There are several movies coming up, including X-Men: Dark Phoenix, New Mutants, and X-Force. However, after that, no one knows. Now that Marvel has the rights back to these characters, we all want to know: how exactly will the X-Men be brought into the MCU, especially since the MCU has gone out of their way to avoid any mention of mutants up to this point, even changing the origins of Scarlet Witch and Quicksilver and trying to use the Inhumans as a way to cover for its lack of mutants. We searched far and wide and found a plethora of ways that Marvel could bring the X-Men into the MCU. From Infinity Stones to the Astral Plane, from the Phoenix Force to Franklin Richards, here are our favorite 20 fan theories about how the X-Men will be brought into the MCU’s continuity.

20 USING THE REALITY STONE TO COMBINE REALITIES

reality-stone

As we saw in Avengers: Infinity War, when the Infinity Gauntlet is used, it is capable of just about anything the user can imagine. As an artifact that houses the Infinity Stones, it is immeasurably powerful, and the power of each individual Infinity Stone is amplified by the Power Stone. The Infinity Stone that some people think will have the biggest impact in the future of the MCU is the Reality Stone. They theorize that the Reality Stone will be used to literally combine the realities of the Fox and Marvel Universes.

This would allow the current set of X-Men actors to continue portraying the characters, particularly the younger, more recently cast actors from X-Men: Apocalypse and the upcoming X-Men: Dark Phoenix.

19 USING THE INFINITY GAUNTLET’S MIND STONE

mind-stone

The MCU already has established a few well-known Marvel mutants during its history, including Scarlet Witch and Quicksilver. Because of these characters, we know that the Mind Stone is capable of empowering heroes that have traditionally been known as mutants.

So why not have the Mind Stone unlock the abilities of more mutants? Maybe someone gets a hold of the Mind Stone and continues the experiments on even more people, or maybe there were just more successful experiments than Baron Von Strucker realized. It would be redefining the origins of the mutants, but it would keep with the continuity established in Avengers: Age of Ultron, so there are benefits and drawbacks to this theory.

18 GALACTUS AND THE PHOENIX FORCE

Another theory out there posits that the Power Stone contains Galactus, who was at some point trapped within the Stone. The Mind Stone, in this theory, would contain the Phoenix Force, which would explain how it empowered Scarlet Witch and Quicksilver.

This would also bring to the MCU two defining adversaries from the histories of two of the biggest groups of heroes that Marvel has reacquired from Fox. In one fell swoop, the MCU would have laid the groundwork to introduce the Fantastic Four and the X-Men. While Galactus and the Phoenix Force have always traditionally been separate entities from the Infinity Stones, there is something about this that makes a little sense.

17 INCURSIONS

In the comics, there is a storyline called "Infinity" in which the heroes have to protect the Earth from collisions with other dimensional Earths as their planes of existence combine into one. Essentially, there is a chain reaction effect of the destruction of realities. These combinations of dimensions are called “incursions” and could be the perfect way to bring the X-Men into the MCU.

The heroes would have to come together to fight for the survival of their universes, and once they win, their worlds could stay united. In fact, this could be one way to explain how the MCU gets repopulated after the Snap destroyed half of the all life.

16 DARK PHOENIX’S POWERS

Dark Phoenix Sophie Turner

With the news of reshoots that occurred late in the process, rumors were rampant about what the X-Men: Dark Phoenix movie could be adding or changing, especially since the news came about after it was confirmed that Disney was acquiring properties from Fox.

Some theorize that these reshoots were to somehow bring the X-Men into the MCU. Perhaps by fully unleashing the power of the Phoenix Force, Jean Grey pulls the X-Men into the MCU. It’s a bit farfetched, and it’s more likely that any reshoots were just a simple part of the production process. It’s also possible that the reshoots were for scenes to add a bit more closure and finality to the Fox X-Men Universe. Don’t count on this one.

15 HIDDEN BY NICK FURY

Marvel representatives have stated that the X-Men will not appear in the MCU for some time, that they hadn’t made any plans before the characters were acquired, and that they will definitely not be in Avengers 4. That hasn’t stopped fans from theorizing that they’ll show up anyway, and that somehow, only Nick Fury knows about them.

Somehow, Fury and Professor X would be working together to maintain the secrecy of Professor X’s school and to downplay mutant attacks as the actions of regular humans. It’s not unlike Fury to have secrets, but could he really hide mutants on an international level? If so, how and when would they come out of hiding?

14 A FULL MCU REBOOT

Infinity War Poster header With Many Of Marvel's Most Famous Heroes Including Black Panther, Black Widow, Hulk, And Spider-Man Front And Center,

What would be the simplest way to introduce the X-Men? Completely end the MCU with Avengers 4 and restart. With several of Marvel’s main heroes gone and others whose actors’ contracts are up, the future of the MCU is uncertain. Even Marvel reps have said that things after Avengers 4 will be an entirely new ballgame, that this is the end of the MCU as we know it.

So maybe they mean that literally. Maybe it’s time to start anew, with a fully populated MCU. Almost all of the Marvel heroes have been onscreen at some point now, and Marvel has a decade of multimedia success to build on. They could make an entirely new thing that is even stronger than the current form.

13 THROUGH DEADPOOL’S TIME TRAVELING SHENANIGANS

Deadpool 2 ended with Deadpool using Cable’s time traveling technology to go through history and fix various things. Who’s to say that his escapades didn’t result in a new timeline in which the X-Men and the MCU are the same?

There would be some plot holes to fill in and a lot of new sense to make of everything, but who better to traverse the insanity of it all than the Merc with the Mouth? His brand of fourth-wall-breaking humor is just the kind of thing that would help the audience navigate the new messy continuity created by the union of the two universes.

12 VIA QUANTUM REALM MANIPULATION

Doctor Strange Quantum Realm 2

The Quantum Realm was first introduced in Ant-Man and then more fully explained in Doctor Strange.Still, it wasn’t until Ant-Man and the Wasp that we really had a chance to spend any significant time within the Quantum Realm and interacting with the surroundings.

We’ve seen the teleporting Quantum effects of the Quantum field in Guardians of the Galaxy Vol. 2. We’ve seen the Quantum effects that exposure to Quantum radiation has had on Ghost and on Janet Van Dyne. We’ve also been told that the Quantum field has time travel effects. Further exploration of the Quantum Realm could unlock the X-Men universe and bring them to the MCU, or the Quantum Radiation could give people powers like it did Ghost and Janet.

11 DOCTOR STRANGE REACHING OUT

Doctor Strange has access to many different planes of reality. It’s entirely possible that his soul lives on after the events of Avengers: Infinity War on the Astral Plane we saw in Doctor Strange. It’s also possible that Doctor Strange is capable of communicating across realities to one in which the X-Men exist.

Doctor Strange also has a history of working with Professor X, as well -- the two were members of the Illuminati alongside Namor, Tony Stark, Black Bolt, and Reed Richards. Whenever the threat level is great enough that the X-Men need to be called upon, Doctor Strange could be the one to do it. Who’s to say what he has seen and who he could pull into the MCU?

10 SECRET WARS!

One of the biggest crossover events in Marvel history, "Secret Wars" gathered a bunch of Marvel heroes and villains from various time periods and universes to fight for the amusement of the Beyonder. They start off fighting each other and end up teaming up to fight the Beyonder.

It’s a simple enough premise for a movie, and could honestly be treated as a two-parter: Avengers vs. X-Men and Avengers: Secret Wars. This could be the way to pull in Fox’s X-Men actors, if Disney wants to retain them. If not, then this is still a great opportunity to recast the characters -- provided they don’t introduce too many new characters at once.

9 MUTATIONS ARE BRAND NEW TO THE MCU

Magneto (Michael Fassbender) in the X-Men films

It could be that the X-Men just appear naturally in the MCU. Perhaps the mutations are a newer development, or perhaps they are just becoming more common in the modern age. Some characters, like Magneto, require a certain backstory, and this is where things get difficult.

Time travel is always a possibility when it comes to superhero stories, but Marvel could give us a movie set in the '60s or '70s. The original X-Men would team up with the original Ant-Man, Goliath, Wasp, Howard Stark, and Peggy Carter. Winter Soldier could be the villain. It would flesh out the history of the MCU a lot and introduce the original X-Men, and it would allow for mutants to be more common in the modern era.

8 PROFESSOR X AND THE ASTRAL PLANE

Patrick Stewart as Professor X

Similarly to how Doctor Strange could reach out to the X-Men, Professor X could also reach across the Astral Plane to find the Sorcerer Supreme and call for help. This kind of thing would be an interesting way to go, especially if Doctor Strange managed to gather a team of heroes to confront and help the X-Men.

Whether the X-Men would be in a different reality or simply a different part of the world could go either way, but really, the relationship between Doctor Strange and Professor X is the important thing to develop for this scenario to really work. They’d need to tease his character in other Doctor Strange movies before fully kicking off this kind of storyline.

7 TRAPPED IN THE SOUL STONE

Soul Stone

This is another theory that requires use of an Infinity Stone, but this theory is an expansion on an Avengers 4 theory. In this theory, the Soul Stone contains the souls of all the beings it has ended, which is evidenced by Gamora’s presence in the Stone at the end of Avengers: Infinity War. Thus, to defeat Thanos and reverse the snap, the Soul Stone must be broken to release all the souls and restore them.

The X-Men could be brought out of the Soul Stone to find themselves in a whole new world, at least to them. This would give the X-Men a fish-out-of-water feeling similar to Captain America, and would allow for the introduction of a number of mutants all at once.

6 THE SNAP ITSELF IS WHAT ACTIVATED MUTANTS

Since, as we’ve mentioned before, the Mind Stone seems to be connected to the powers given to Scarlet Witch, Quicksilver, and Vision, it isn’t a big stretch to think that maybe the Mind Stone is responsible for other mutants. But what if it’s not just the Mind Stone, but it’s Thanos himself that’s responsible?

The Snap, with its extremely widespread effects, could have instantaneously gifted a bunch of people with mutations and abilities akin to the X-Men. While this would be a huge rewriting of X-Men history, the great thing about Marvel is that they always find a way to make it work. Maybe the Mind Stone and the Time Stone worked in conjunction to instill mutations across the timeline.

5 THEY'RE FROM THE FUTURE

The X-Men travel through time rather often, and the Age of Ultron miniseries is no exception. In this storyline, the X-Men travel from the future to stop Hank Pym from creating Ultron.

A similar movie could be pretty interesting; the mutations could be a thing of the future, and the mutants could end up stranded back in our time. Which mutants would make this trip is anyone’s guess, but it would at least introduce the idea that there are timelines in which there are mutants. This would also give audiences another look at the dangers of Hank Pym’s irresponsible science. Even if Ultron himself isn’t the danger being thwarted, Pym’s experiments with the Quantum Realm could cause all kinds of problems.

4 BLACK PANTHER INTRODUCES STORM TO THE MCU

Black Panther Chadwick Boseman

If anyone is good at keeping a secret, it’s the inhabitants of Wakanda, who manage to keep their entire nation hidden from the outside world. Because of this, it’s not impossible to think that the Wakandans might be aware of another nation, Genosha. This nation has served as both a threat and a sanctuary to mutants.

Why would Black Panther know about this? Because both are advanced civilizations that couldn’t avoid discovering each other. However, as comic fans know, Black Panther ends up marrying Storm and introducing Storm would therefore be a great way to develop the various relationships in Black Panther 2.

3 HEREOS REBORN

"Heroes Reborn" is not just the name of the attempted revitalization of the Heroes TV series -- it's also the name for a storyline in which Franklin Richards transported several Marvel superheroes into a microverse of his own imagining. Essentially, Franklin Richards can create and destroy realities at will, as well as transport the inhabitants from one universe into another.

This could easily explain either of the MCU or Fox universes -- one could be the real thing, the other could exist in the imagination of Franklin. Franklin could also easily pull X-Men from the Fox movies into the MCU. Marvel would have to introduce the Fantastic Four first, but a decent Fantastic Four movie is long overdue.

2 A SERIES ON DISNEY'S NEW STREAMING SERVICE

Ultimate X-Men David Finch

In season three of Daredevil, Ben “Dex” Poindexter took on the appearance of Daredevil and fought his way through Hell’s Kitchen, eventually breaking his back at the hands of none other than Wilson Fisk. When his spine is reconstructed, a familiar name is dropped, that of Doctor Oyama.

Oyama is a Marvel scientist that is most often associated with the Weapon X program and the method of surgery used to graft adamantium onto Wolverine’s spine. That the character shares a history with the X-Men is notable, and suggests that perhaps Disney’s new streaming service might be the platform on which the X-Men next emerge.

1 THE SKRULLS AND SECRET INVASION

Talos with Skrulls on the beach

Captain Marvel is going to introduce the Skrulls to the MCU, and will take place in the '90s, firmly establishing MCU history in a manner that hasn’t been done since Captain America: The First Avenger. The important thing here is that the Skrulls are shapeshifters, and in one of Marvel’s biggest storylines, the Skrulls take over the identities of several well-known Marvel superheroes.

Many think that this means the "Secret Invasion" storyline will be the MCU’s next big event. The Skrulls could have taken on the identities of several X-Men as well as the heroes we are familiar with, which could set up for more mutants to be introduced down the line.