The Marvel Cinematic Universe is arguably the most popular franchise currently in existence. Given its popularity and extensive source material from the comics, it's not at all surprising that fans are constantly generating new theories about the superhero universe. Certain theories inevitably come true and it is generally rewarding for fans when this happens. Some theories have simply been confirmed by occurring in MCU movies or trailers. Others have been confirmed on social media or in interviews with some of the MCU's most notable directors and actors.

Many fan theories have been confirmed over the years, yet countless others are still just theories. This article will look at some theories that haven't been confirmed yet but should be, many of which relate to the events of the highly-anticipated Avengers: Endgame. Some other theories that deserve to be confirmed relate to the future of the X-Men and the Fantastic Four in the MCU. With so many theories out there that still haven't been confirmed, this article will try to focus on some of the most fascinating, yet plausible theories that fans have created.

So sit down and grab some shawarma as we explore the 11 MCU Fan Theories That Were Actually Confirmed (And 11 That Should Be).

22 Confirmed: Peter Parker Appeared In Iron Man 2

Tom Holland confirmed the longtime fan theory that Peter Parker was in Iron Man 2. A child wearing an Iron Man mask boldly stands his ground when confronted by one of Justin Hammer's drones. He is saved by Tony Stark who says, "Nice work, kid" before flying off to help other endangered citizens.

The theory confirms that Peter appeared in the MCU long before Spider-Man was officially part of the superhero universe. Part of the reason this idea works so well is that the MCU's Peter is so closely connected with Tony. It's more meaningful to think that Peter admired Iron Man from such a young age and was inspired to be a hero by Iron Man, something shown in Peter's actions when standing up to the drone in this scene. The fact that Tony saved Peter's life as a young child makes the final scene between them all the more heartbreaking in Avengers: Infinity War.

21 Could Be: The Soul Stone And Ancestral Plane Are Linked

Many beloved MCU characters fell prey to Thanos' snap at the end of Avengers: Infinity War, including the Black Panther, T'Challa. Some fans have theorized that these individuals are not fully deceased, but that their souls have just been displaced into the Soul Stone. Meanwhile, the ancestral plane played a pivotal role in Black Panther, a place where a soul can exist outside the body and the Black Panther is able to communicate with their ancestors.

All of this talk of souls has certain fans thinking that the Soul Stone and ancestral plane may be linked, as they are both places where souls can exist and interact outside the body. If this is true, the new Black Panther following T'Challa's demise could enter the ancestral plane and use its connection to the Soul Stone to find and possibly free the souls that Thanos displaced there when he snapped his fingers. If this is true, the ancestral plane could be the key to bringing back to life those who perished as a result of Thanos' snap.

20 Confirmed: Groot Perished In Guardians Of The Galaxy

After the first Guardians of the Galaxy, most fans were under the impression that Groot hadn't perished, and had essentially just become baby Groot. Fans arguing that the original Groot did lose his life had their theory confirmed by James Gunn. Gunn asserted that the original Groot perished at the end of that movie and baby Groot is the original's son.

Confirmation of this theory is devastating and raises a number of questions. At the very least, the theory makes the first Guardians of the Galaxy even stronger, as it lends more weight and lasting impact to Groot's sacrifice. It also makes even more sense for teenage Groot's last words in Infinity War to be "Dad." Rocket raised baby Groot -- now teenage Groot -- as his father never could because of the original Groot's sacrifice in Guardians of the Galaxy.

19 Could Be: Odin And Hela's Infinity Stone Quest

For all of its silliness, Thor: Ragnarok was a surprisingly thought-provoking movie. Much of this came through the revelation that the seemingly noble Asgardian empire was built off the treacherous conquests of Odin and Hela. The forgotten tapestries that Hela unearthed reveal the bloodshed that she and Odin caused in their quest for power and domination.

Such motivations certainly hint at the theory that Odin and Hela also quested after the Infinity Stones. The theory goes further to suggest that it was seeking the Soul Stone that changed Odin's heart. As fans know from Thanos sacrificing Gamora in Infinity War, Odin would've had to sacrifice the person he loved most in order to obtain the Soul Stone. Unable to sacrifice his own daughter, Odin would not only have failed to acquire the Soul Stone, but also have realized that conquest was wrong. This would explain why Odin changed his philosophy.

18 Confirmed: Red Skull Survived

Many fans were convinced that Captain America: The First Avenger was not the end of Red Skull. The villain was seen being blasted into the cosmos by the Tesseract/Space Stone, but it didn't seem like a definitive end and definitely left the door open for the character's return. Over time, such a return seemed less and less likely as the MCU continued to roll on without an appearance of Red Skull.

Those who continued to stand by the theory were rewarded in Avengers: Infinity War when Red Skull resurfaced. He was confirmed to not only have survived, but he was also the one guarding the mysterious and much coveted Soul Stone on the planet Vormir. As Red Skull was one of the first villains shown to seek after an Infinity Stone, it seemed like poetic justice that he was forced to guard another Infinity Stone without being able to possess it for many years.

17 Could Be: Magneto Is Wanda And Pietro Maximoff's Father

It is a widely known fact that in the X-Men comics, Magneto is the father of Wanda and Pietro Maximoff. It's been far more complicated in the MCU where Wanda and Pietro were introduced in Avengers: Age of Ultron, but conflicting rights prevented the X-Men from being part of the story. That looks to change considering Disney's merger with Fox.

Revealing Wanda's father to be Magneto would be a smart way to begin bringing the X-Men into the MCU, as they'd be so closely linked to an established, well-developed character like Wanda. The MCU's limited television series centering on Wanda would be a prime opportunity to confirm this theory and use her to help establish Magneto and the X-Men.

16 Confirmed: The Real Mandarin Exists

A number of fans were disappointed that the Mandarin wasn't a formidable villain in Iron Man 3. In fact, the person everyone thought was the Mandarin was actually washed-up actor Trevor Slattery who was essentially being used as a cover for Aldrich Killian's schemes. This twist didn't stop fans from theorizing that the real Mandarin was still out there, though.

Fans got their wish in the short movie All Hail The King, where it was revealed that the real Mandarin did exist. He even executed a plan to break Trevor Slattery out of prison so the actor could face the consequences of portraying himself as the Mandarin. The MCU hasn't done anything with the Mandarin since All Hail The King was released, but at least fans know there's a possibility that the iconic Iron Man villain can be used in future MCU stories.

15 Could Be: The Fantastic Four Bought Stark Tower

Stark Tower being sold was an important plot point in Spider-Man: Homecoming, particularly concerning the transportation of certain items from Stark Tower. Despite this, the movie never revealed who actually bought Stark Tower. Some fans have theorized that the mysterious buyers are actually Reed Richards and the Fantastic Four.

The Fantastic Fours' headquarters, known as the Baxter Building, is located in the heart of New York City. It's possible that Stark Tower will serve as the MCU's equivalent of this building, or that the Fantastic Four will rename their purchased property as the Baxter Building. Much of the conversation about how the Disney-Fox merger will influence the MCU's future seems to revolve around the X-Men. It's important to remember that the Fantastic Four will likely be brought into the MCU as well. Fortunately, Spider-Man: Homecoming may have already planted the seed for the Fantastic Four's MCU debut.

14 Confirmed: All Of Stan Lee's Cameos Connect

Stan Lee's cameos were always a delight to see, but at a certain point, fans started to wonder if his appearances were more significant to the narrative than just fun cameos. A theory formed that all of Lee's cameos were actually connected. This theory was confirmed in Guardians of the Galaxy Vol. 2 when Lee's character was seen interacting with a group known as the Watchers and recounted the time he was a postman. This was a clear reference to his cameo as a FedEx postman delivering a package for "Tony Stank" at the end of Captain America: Civil War.

Kevin Feige confirmed that this scene is supposed to solidify that Lee has actually been playing the same character in every single MCU movie. Lee is credited as a "Watcher Informant," which suggests that he is not a Watcher himself, but informs the Watchers on what he's observed in his many other guises.

13 Could Be: Charles Xavier Wiped Everyone's Minds

The Professor X Mindwipe theory is a popular one concerning how the MCU will eventually incorporate the X-Men given the Disney-Fox merger. It's certainly a challenge to introduce the concept of mutants considering that their existence hasn't even been acknowledged in the MCU. This theory suggests that mutants haven't been mentioned because Charles Xavier wiped everyone's minds in the MCU of the knowledge that mutants exist.

Rationale for the theory rests in the fact that Professor X wanted to protect mutants from the increasing hostilities of humanity. If humanity didn't know about mutants, they could no longer create devastating conflicts against mutants. It can explain why mutants haven't been seen or talked about without creating countless plot holes. The most intriguing part is what would motivate Professor X to do this.

12 Confirmed: The Winter Soldier Assassinated Tony Stark's Parents

Captain America: The Winter Soldier revealed that HYDRA had infiltrated S.H.I.E.L.D. for decades. HYDRA even terminated key members of S.H.I.E.L.D via an assassin known as the Winter Soldier, who was Captain America's friend Bucky Barnes. This led some fans to speculate that the Winter Soldier was responsible for the demises of Tony Stark's parents. Howard Stark was a longtime and essential member of S.H.I.E.L.D and his passing was supposed to look like a tragic accident, something that insightful fans realized had all the markings of a targeted mission from HYDRA and the Winter Soldier.

These fans had their theory confirmed when it was revealed in Captain America: Civil War that HYDRA's prized assassin was indeed behind the demises of Howard and his wife Maria. Tony Stark learning the truth was a major plot point in Civil War and was a crucial aspect of the rift that formed between him and Captain America, as Cap continued to defend Bucky in spite of this past crime.

11 Could Be: Uncle Ben's "Old Movies" Legacy

Peter Parker hasn't been in the MCU long, yet he's already developed a reputation for developing plans loosely based on "old movies" like Star Wars: The Empire Strikes Back and Aliens. In the beginning of Spider-Man: Homecoming, Peter also showed a penchant for film-making.

A touching fan theory is that Peter's love for "old movies" and film-making is rooted in his relationship with Uncle Ben. The theory suggests that Uncle Ben was the one to show Peter movies like The Empire Strikes Back and Aliens. It goes further to argue that Peter's homemade movie at the beginning of Homecoming is really meant for Uncle Ben. In the larger scheme of the MCU, the theory may seem insignificant, but it's a sweet way of solidifying a legacy for Uncle Ben -- of whom almost nothing is known about in the MCU -- and it adds more significance to those "old movies" Peter loves so much.

10 Confirmed: Bruce Banner In The Hulkbuster Armor

The trailers leading up to Avengers: Infinity War featured a few shots with someone fighting in the Hulkbuster armor in Wakanda. Tony Stark designed the Hulkbuster armor and had worn it in the past. None of the trailers featured shots of Tony in Wakanda, though, which begged the question of who was inhabiting the Hulkbuster armor if it wasn't Tony. Even though there was a shot in the trailers of the Hulk in Wakanda, some fans predicted that it was Bruce Banner in the Hulkbuster.

Their prediction came true in Infinity War, as Bruce Banner fought in the Battle of Wakanda by using the Hulkbuster. Other than a fight against Thanos in the very beginning of the movie, the Hulk refused to come out and fight this time around, so using the Hulkbuster was the best alternative for Bruce to use on the battlefield.

9 Could Be: Tony Stark And The Infinity Gauntlet

Doctor Strange made a game-changing decision when he willingly handed over the Time Stone to Thanos in exchange for Tony Stark's life. Having seen the one possible future where the Avengers defeat Thanos, it's clear that Doctor Strange knew Tony had an essential role to play in undoing the snap and defeating Thanos in Avengers: Endgame.

One fan theory is that Tony's essential role revolves around the Infinity Gauntlet. As it was wielding the Infinity Gauntlet and all the Infinity Stones that allowed Thanos to wipe out half the life in the universe in the first place, it stands to reason that wielding the Infinity Gauntlet again will be the only way to undo the devastation. At the end of Infinity War and in the first trailer for Endgame, it appears that the Infinity Gauntlet is damaged, so fans are theorizing that Tony will use his genius to repair it.

8 Confirmed: Hawkeye Will Return As Ronin

Hawkeye was conspicuously absent in Avengers: Infinity War. With all the other original Avengers alive at the end of Infinity War, fans agreed that Hawkeye had to be alive as well and would return in a big way. The most popular theory was that he would return as Ronin, the darkest iteration of Clint Barton from the comics.

The first trailer for Avengers: Endgame confirmed not only the return and survival of Hawkeye, but that he would return as Ronin. The general thought is that Hawkeye's family, which was revealed in Avengers: Age of Ultron, perished when Thanos snapped his fingers, a tragedy that would certainly send Clint down a darker path than what fans have previously seen from him in the MCU.

7 Could Be: How Ant-Man Will Escape The Quantum Realm

The mid-credits scene for Ant-Man and the Wasp increased the cliffhangers left at the end of Infinity War. Hope van Dyne -- along with her parents Janet van Dyne and Hank Pym -- perished when Thanos snapped his fingers. Ant-Man survived, but the untimely demises of the Pym/van Dyne family left him stranded in the Quantum Realm. The first trailer for Avengers: Endgame reveals that he makes it out of the Quantum Realm, though it does not answer how he achieves this.

Some fans think the answer to this question lies in what Janet told Scott right before he entered the Quantum Realm in the mid-credits scene. Janet warned him about not getting sucked into a time vortex. The specificity of this warning was obviously intentional, hinting that Scott will need to use a time vortex to travel through time and space in order to escape the Quantum Realm.

6 Confirmed: Valkyrie Survived Thanos

Tessa Thompson made a big splash in the MCU with her portrayal of Valkyrie in Thor: Ragnarok. This left some fans disappointed when Infinity War didn't reveal what happened to Valkyrie, even though she was aboard the ship Thanos attacked at the beginning of the movie. Since her demise wasn't shown, fans theorized that Valkyrie survived the attack from Thanos and his Black Order.

Infinity War co-director Joe Russo confirmed that Valkyrie survived the attack at the beginning of the movie. Tessa Thompson herself confirmed that Valkyrie survived Thanos a second time, as she did not fall victim to the snap. It's satisfying to know that Valkyrie is still alive, which hopefully means that she will not only appear in Avengers: Endgame, but that she could also play a meaningful role in the film.

5 Could Be: Winter Soldier Will Be In The Black Widow Movie

Phase 4 of the MCU is still largely a mystery, but one thing audiences are getting for sure is a long overdue Black Widow movie. The plot of the movie remains unknown, though it will likely provide insight into Black Widow's past. There are many advocates for this focus on her past to include the Winter Soldier, a possibility that Winter Soldier actor Sebastian Stan would like to see come to fruition.

He and Black Widow have a rich and complex history in the comics. Their pasts are connected in the MCU, though the specifics are vague. Having the Winter Soldier be a key player in the Black Widow movie would provide tremendous insight into their backstories and MCU history. It would even enrich the Winter Soldier movie, as it would give more weight to Black Widow's role in risking everything to take down HYDRA's assassin in the movie.

4 Confirmed: Red Skull Is Now Free

Avengers: Infinity War surprised many audiences when revealing that Red Skull was not only alive, but had been guarding the Soul Stone on Vormir for decades. As Thanos sacrificed Gamora and in doing so acquired the Soul Stone, many fans wondered if Red Skull was now free. Joe and Anthony Russo confirmed that Red Skull is now free to leave Vormir and is once again able to pursue the Infinity Stones.

Just because Red Skull can once again pursue the Infinity Stones doesn't mean he will, though. Seeking after the Tesseract/Space Stone put him on a path where he was forced to guard the Soul Stone for decades. A villain of Red Skull's potential definitely needs to return to the MCU, but after the high price he's paid and everything he's seen Thanos, Gamora, and countless others pay in their quest for the Infinity Stones, Red Skull may have a different agenda when fans see him next.

3 Could Be: Captain Marvel Will Save Tony Stark And Nebula

The answer of how Tony Stark and Nebula will survive their predicament in space may lie in the answer of where Captain Marvel has been for the last decade and how she'll convince the Avengers to trust her. One theory that addresses all of these questions is that Captain Marvel will be the one to save Tony and Nebula. The theory posits that Captain Marvel will leave Earth and focus on fighting cosmic conflicts at the end of her own movie.

At the beginning of Avengers: Endgame, though, she'll be on her way back to Earth after the message she got from Nick Fury. She'll cross paths with Tony and Nebula, save their lives, and help them all get back to Earth. This act will convince not only Tony and Nebula to trust her, but will also convince the Avengers and Rocket -- the only remaining Guardian of the Galaxy after Thanos' snap -- to trust Captain Marvel.

2 Confirmed: Endgame Will Feature The Battle Of New York

Set photos from Avengers: Endgame confirm the fan theory that the movie will feature the Battle of New York from The Avengers. Considering that the original MCU Avengers survived Infinity War and will be a major focus of Endgame, it is fitting to return to the battle where they first truly united. It is also fitting since Endgame is a culmination of the entire MCU so far, a story that began with these original Avengers.

Many fans believe seeing the Battle of New York again is proof of the Avengers using time travel as part of their plan to reverse the effects of Thanos' snap. While some of the set photos depict the same Battle of New York that fans remember, other set photos include key differences, such as the inclusion of Ant-Man. Set photos like the latter have led fans to think aspects of the Battle of New York could be changed via time travel this time and that it won't just be a flashback.

1 Could Be: Trask Industry Experimentation

When considering X-Men characters who could already exist in the MCU, some fans have theorized that Bolivar Trask and his company Trask Industries could already exist. The theory is that Trask Industries is operating in secret and experimenting on Inhumans. Given the Disney-Fox merger, it's also possible that Trask Industries could be experimenting on mutants. Their secret experiments could help explain why mutants have been absent from the MCU.

This theory doesn't just have to tie in with the movies, though. It could first tie into MCU television shows like Agents Of S.H.I.E.L.D where Inhumans have received a lot of focus, or possibly in the future limited series focused on Wanda Maximoff as that series might introduce mutants into the MCU.


What other MCU fan theories have been confirmed or do you think could be confirmed? Sound off in the comments!