What will be the MCU's next Infinity War? Marvel Studios is currently wrapping up their first saga with Avengers: Infinity War and Avengers 4, a two-part culmination of the Marvel Cinematic Universe to this point. But, with Marvel's shared universe model, another major event is all but guaranteed to come - but what should it be?

Over the last ten years, the MCU has been building towards a single major event. The movies have been largely been centered around the original six Avengers: Iron Man, Captain America, Thor, Black Widow, Hulk, and Hawkeye. From their first team-up in The Avengers, it was clear the ultimate end-game was Mad Titan Thanos, teased in the post-credits scene. Dozens of other characters have been introduced since, but the original Avengers and Thanos are still the cornerstone pieces of the MCU.

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For the purposes of the long-awaited clash, there are two comic stories that appear to have had the most influence. Jim Starlin's Infinity Gauntlet event from the early 1990s has several similarities and has the original Thanos snap. But, Jonathan Hickman's Infinity run from 2013 is also confirmed the be a major source of inspiration for the story. But once this story comes to a close, the MCU will need to chart course for a new event.

The MCU's Phase 4 Needs To Start A New Event Story

With Avengers 4 serving as the conclusion of the eleven-year story that will span 22 movies, MCU Phase 4 and beyond will look very different. Most of the original Avengers will likely not be around anymore and new properties like The Eternals will be introduced with the possibility of being new, major MCU franchises. This doesn't even account for the impending additions of the X-Men and Fantastic Four, who should become staples of the MCU. Plus, characters like Captain Marvel, Black Panther, Spider-Man, and Doctor Strange will continue to rise to prominence.

Since all of these characters will still live in the same universe, it keeps the doors open for future crossovers, both big and small. Despite any scheduling headaches that the scope of production on Avengers: Infinity War and Avengers 4 caused Marvel, they are seeing enormous returns financially. Infinity War made over $2 billion worldwide and expectations are high for Avengers 4's box office performance. There's no way the MCU won't eventually have another major crossover event, and thankfully there are quite a few events from the comics that can be adapted next.

Annihilation Conquest

One potential fit could be the MCU's take on Annihilation Conquest. This crossover event came from Dan Abnett and Andy Lanning in 2007 as a sequel event to 2006's Annihilation. The story puts the cybernetic species known as Phalanx at the center of the conflict as their infection enslaves the Kree and use their homeworld of Hala as their base of operation. It is revealed that Ultron has taken over the species and ruling Hala is just the beginning. In order to try and stop Ultron's galactic overtaking, Phyla-Vell aka Quasar and Moondragon set out to find a "savior" - only to discover a reborn Adam Warlock. From there the story focuses on a team of mercenaries run by Ronan the Accuser, a new Guardians of the Galaxy team, and many other cosmic characters all attempting to foil Ultron.

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The MCU has yet to really establish most of the biggest aspects of Conquest to this point, so it would take some time to properly build to such an event. The introductions of Phyla-Vell and Moondragon are important, especially considering how integral they are to the story's emotional beats. Adam Warlock also still needs to be introduced and Guardians of the Galaxy Vol. 3 could make that happen, but that movie may still be several years away. Captain Marvel will truly introduce the Kree and Hala next year, so the set up for one of Conquest's main locations will then be available. Ultron's involvement wouldn't be too difficult to make work in canon either, as his fate in Avengers: Age of Ultron was extremely vague; they could explain that he was stalling in conversation with Vision as he uploaded his A.I. to a distant technological race like the Phalanx. And, since Ronan died in Guardians of the Galaxy, Jude Law's mysterious Captain Marvel character could potentially serve as Ronan's replacement, if he survives.

The future of the MCU may be very cosmic oriented, so a truly cosmic event for their next saga makes sense. This would potentially eliminate the participation of some major Earth-based heroes, but that same thought process didn't stop Spider-Man from going to Titan in Avengers: Infinity War. Major heroes like Captain Marvel and Black Panther could take inspiration from the Ultimates to go cosmic, while the MCU's take on this story could also include The Eternals and other future cosmic characters like Nova (who is part of the comic story) or soon to be additions in the Fantastic Four and X-Men. The threat of Ultron and the Phalanx taking over the galaxy would be worthy of calling all of the MCU's heroes together, while also allowing for the event to leave Earth behind. And even if Avengers 4 is titled Avengers: Annihilation, simply subtitling this new event Conquest can get the job done while eliminating the risk of confusing casual audiences.

Page 2: Secret Invasion & X-Men Takeover

Skrulls impersonate superheroes in Marvel Comics.

Secret Invasion

In terms of a sprawling tale that demands years of set up, Secret Invasion could be the most likely choice for the next major event of the MCU. The story came from the mind of Brian Michael Bendis in 2008, coincidentally enough as the fallout of the Annihilation event. Secret Invasion shows the results of a master plan by the shapeshifting alien race known as the Skrulls to infiltrate Earth and assume the identities of key government officials, various people of power, and superheroes. The series strips all trust between the reader and the various characters due to no one knowing if anyone really is who they say they are. It ultimately reveals that several key heroes have been Skrulls for years.

Although there have been theories that Captain Marvel or even Avengers 4 could be the MCU's take on Secret Invasion, each would be better served as laying foundational work for a future crossover. Captain Marvel is doing some of the heavy lifting here with the introduction of the Skrulls and its focus on the Kree-Skrull war. In the comics, the outcome of the war is a motivating factor for the Skrulls to start their infiltration of Earth. They likely won't be the victors in the MCU's version either considering we've yet to see them after the 90s era battle, but rumors have claimed they could have a small role in Avengers 4 as well.

Related: Captain Marvel Theory: It's Actually The MCU's Secret Invasion

One of the great advantages to Secret Invasion is it can work on the premise almost regardless of which characters are involved. This means that the new faces of the MCU that rise in Phase 4 and beyond can be the main heroes of such an event, just like how the original Avengers are key to the current saga. Marvel can take their time subtly making small character changes throughout the several years of storytelling, and then reveal down the line that some major MCU characters haven't been themselves. It would be as universe altering of an event as Thanos' snap, but the mystery element at the heart of the story allows Marvel to do it in an entirely new way.

Avengers vs X-Men

Avengers vs X-Men comic book

Depending on how Marvel Studios incorporates the X-Men, the next saga could very well be an adaptation of Avengers vs X-Men. The comic story revolves around an impending attack by the Phoenix Force on Earth, which is believed to be coming for Hope Summers. Captain America and the Avengers want to be the protectors of Hope, but Cyclops and a select group of X-Men believe otherwise. This is the start of the conflict and in an effort to defeat Phoenix, the energy is transferred to Cyclops, Emma Frost, Namor, Colossus, and Magik. From there, the "Phoenix Five" as they become known rise to power and the battle for Hope's future continues to bring the two super teams to blows.

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Disney is in the process of acquiring 21st Century Fox's assets and the deal will finally bring Marvel's mutants under the MCU umbrella. Their plans for the X-Men have yet to be revealed, but a steady build-up should be expected. Assuming this happens at some point in Phase 4, the MCU can then continue to grow the X-Men over the span of multiple years. The group dynamics and relationships with the rest of the MCU heroes can be established during these times, setting up the different ways of thinking each group has. Ultimately, it can conclude with this major crossover that could bring even more MCU stars together than even Avengers: Infinity War and Avengers 4 can claim.

It would essentially be an even larger version of Captain America: Civil War, but done without a villain manufacturing the friction. Avengers vs X-Men would be a true team of heroes vs team of heroes movie that could have a lasting impact on the universe moving forward. It's got everything Marvel could want in their second saga that also avoids many similarities to what they're currently doing. And since it is hard to imagine the X-Men not being heavily involved in whatever the next saga is, then putting them at the focus just makes sense.

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