The Marvel Cinematic Universe is preparing for a big change with the upcoming release of Ant-Man & the Wasp: Quantumania. The film will see Paul Rudd's Scott Lang come face-to-face with Kang the Conqueror, the new Thanos-level threat in the Marvel universe. This will also serve as the official start to the MCU's Phase 5 slate of upcoming films.

RELATED: MCU: Things Fans Can Expect From The Fantastic Four Movie

Given the impending storylines that will come to fruition before the release of Avengers: Secret Wars, there are many characters from the comics who may play a big role in the stories to come. However, some of them have either not been cast, or haven't been confirmed to appear. These characters are who fans are anxious to see the most.

10 Reed Richards

Reed Richards working with holograms in the comics

One of the most anticipated projects in the MCU's Phase 6 is Fantastic Four, which will reboot one of Marvel's most famous superhero teams for the second time. Their existence in the MCU has already been teased, with John Krasinski appearing as an Illuminati variant of Reed Richards in the 2022 film Doctor Strange in the Multiverse of Madness.

For the Fantastic Four movie, however, Krasinski will likely not be reprising his role. However, there are many names that have popped up in rumors regarding the film's casting, including Penn Badgley, Dev Patel, and Adam Driver. It's unclear as of now who will become the MCU's smartest man alive, but whoever it is will have quite a weight on their shoulders.

9 Sue Storm

Sue Storm putting up a forcefield in the comics

With the addition of Reed Richards also comes the introduction of another Fantastic Four member: Sue Storm. As the sister of Johnny Storm, a.k.a. the Human Torch, Sue Storm masquerades as the superhero known as Invisible Woman. However, Sue Storm also plays a vital role in the Marvel universe as the spouse of Reed Richards and the mother of their children.

RELATED: MCU: All Of Phase 4, Ranked

Previously, the character was played by Jessica Alba and Kate Mara in film adaptations. However, rumors have circled naming actresses like Mila Kunis and Jodie Comer as potential castings for the character. Her parentage with Reed Richards will also potentially result in the future lineage including the likes of Kang the Conqueror's first version, Nathaniel Richards.

8 Doctor Doom

Doctor Doom reaching for a crow in a comic cover

With the promise of the Fantastic Four and Avengers: Secret Wars on the horizon, many fans are anxiously awaiting the reveal of Victor von Doom, one of the most powerful villains in Marvel history. The Latverian ruler known as Doctor Doom plays a major role in Marvel's multiversal conflicts, which may spell doom for the current cast of Marvel favorites.

Following a multiversal collapse caused by incursions, Doctor Doom creates the Battleworld, a patchwork planet made of pieces from other multiverses. Rumors have suggested the Battleworld will be the setting of the MCU post-Phase 6. With this in mind, fans want to know who will be the MCU's Doctor Doom for what seems like the inevitable future.

7 Nova

Nova standing out in the stars in the comics

The character of Nova has had many different interpretations in the world of Marvel Comics. There was the original Nova, Richard Rider, an officer of the intergalactic police force known as the Nova Corps (who debuted in the first Guardians of the Galaxy). There's also Sam Alexander, a younger character who inherits the title and later becomes an Avenger.

It's been rumored that Nova will be making his debut in either a Disney+ series or special, though the identity of which Nova they'll be introducing is unknown. However, actors like Brandon Perea, who appeared in Jordan Peele's 2022 film Nope, have already thrown their names in the ring to play the cosmic cop in the Marvel Cinematic Universe.

6 Gwen Stacy

Gwen looking at Spider-Man in a comic cover

2021's Spider-Man: No Way Home reshaped the MCU iteration of Peter Parker's life, killing off Aunt May and erasing everyone's memory of him. Nevertheless, the film ends with Peter, in a self-made Spider-Man suit, continuing to be present in New York City. Kevin Feige even confirmed recently that a future for Tom Holland's Peter Parker was in the works.

RELATED: MCU: Possibilities For The Next Tom Holland Spider-Man Movie

Given that Peter has lost touch with Zendaya's M.J., it's due time for Peter to get a new romantic interest. This could lead to the potential of introducing Gwen Stacy into the life of Holland's Parker. The character serves a much different, albeit more tragic, function to Peter Parker than the comic M.J., as seen by Emma Stone's portrayal in the Andrew Garfield films.

5 Miles Morales

Miles Morales in his black-and-red costume summoning lightning in the comics

Speaking of Spider-Man, the early traces of Miles Morales' existence in the MCU were teased in 2017's Spider-Man: Homecoming. In the film, Donald Glover played Aaron Davis, Miles' uncle and a thief known as the Prowler. In one deleted post-credits scene, Aaron can be seen on the phone with his nephew Miles, though Miles was never seen on-screen.

Miles later made his film debut in the animated movie Spider-Man: Into the Spider-Verse, which explored the multiverse. The existence of a black Spider-Man was again hinted at in No Way Home by Jamie Foxx's Electro. Given that Marvel is continuing to explore the multiverse, hopefully, it won't be long before fans get to see a live-action Miles Morales.

4 Magneto

An older Magneto sitting in the comics

Patrick Stewart notably reprised his role as Professor X in Doctor Strange in the Multiverse of Madness. Though the character had a proper send-off in 2017's Logan, the future of Stewart in the role is up in the air. Recently, Stewart hinted at reprising the role in Deadpool 3 alongside Hugh Jackman, who is confirmed to be returning as the mutant Wolverine.

However, one significant mutant whose casting is unknown is Max Eisenhardt, a.k.a Magneto. The character has been portrayed by Ian McKellan and Michael Fassbender in previous films, though there's no indication either of them will return. The character's relationship with Elizabeth Olsen's Scarlet Witch could also be a major part of his re-entry.

3 Moondragon

Moondragon lifting her hand in the comics

2023 will also, sadly, mark the end of the current lineup of James Gunn's Guardians of the Galaxy with the final entry in the trilogy. It's unknown what shape the Guardians will take without some key members, but luckily empty seats mean new characters to fill them. One rumored character to be taking the place of another is Heather Douglas, a.k.a Moondragon.

RELATED: The Best Movie Soundtracks To Study To

Once a Californian girl, Heather's family were victims of Thanos, with her father's soul later becoming Drax the Destroyer. The character later becomes an unofficial member of the Guardians, as well as an ally of Adam Warlock, who is set to debut in Guardians of the Galaxy Vol. 3, though it's unknown if Moondragon will also appear in the film in some way.

2 Squirrel Girl

Squirrel Girl with a squirrel in a comic cover

The character of Squirrel Girl is an unexpectedly strong one in the Marvel comic universe. There have previously been plans to adapt the character into live-action, with Milana Vayntrub attached to play Doreen Green in Freeform's canned New Warriors series. However, given the character's fan-favorite status, it's likely she'll show up eventually.

Some rumors have suggested the character has just recently been cast. Emma Corrin was confirmed to be playing a villain in Deadpool 3, which some fans have speculated could be Squirrel Girl, which would certainly fit the tone of Ryan Reynold's Marvel escapades. Since it's unknown, however, Squirrel Girl's potential casting remains a mystery.

1 Beyonder

The Beyonder toying with a hero in the comics

Next to Doctor Doom, Beyonder is another character who is vital to Marvel's multiversal antics. The character is an omnipotent force that controls Marvel's greatest heroes, forcing them to battle each other in the first iteration of the Battleworld. Future retcons turned the character into a mutant Inhuman, or a descendent of a race of Beyonders.

Nevertheless, Beyonder would be quite the cosmic higher stakes that the MCU might need heading into future phases after Phases 5 & 6. Whatever direction Marvel is heading in, they will definitely be testing the limits of their most popular characters. Hopefully, fans learn more about the future of their favorite franchise within the coming year.

MORE: MCU: Best Characters In Phase 4 (So Far)