Marvel Studios revealed at San Diego Comic-Con that the sixth Avengers movie will be titled Secret Wars, and cap The Multiverse Saga. Secret Wars shares its name and likely many story elements with 2015's massive storyline, in which the entire Marvel multiverse collapses thanks to incursions, and only one integrated universe called Battleworld remains.
Many details from the storyline, including bringing together countless characters from different timelines and realities, probably carry over into the movie. Some aspects may change, as Kang The Conqueror, the clear villain of the MCU Multiverse Saga, doesn't play a role in the comic books. He does in the original 1985 Secret Wars limited series, which may also lend inspiration to the highly anticipated movie.
Time Runs Out
Secret Wars begins with the end, literally. Writer Jonathan Hickman lays the groundwork for the epic storyline in many different comics over many years, including Time Runs Out. This storyline sees incursions multiply throughout the multiverse, destroying them until finally Earth-1610 and Earth-616 collide with each other in Avengers #44.
This issue brings together numerous story threads running through the comics at the time, including the growing conflict within the Illuminati. Doctor Strange in the Multiverse of Madness.
Incursions
The recent movie also introduced incursions, which play a critical role in Secret Wars. Incursions in the comics arise from another universe's contraction, and the ripple effects spread through the multiverse, forcing individual ones to collide with each other. This ripple eventually becomes a cascade, leading to the entire multiverse unraveling.
The incursions all occur at their respective universe's Earth, which allowed the Marvel superheroes to witness the impending collision between Earth-616, the main Marvel Universe, and Earth-1610, the Ultimate Comics universe where Miles Morales originated.
Destroying A World To Save Another
As Earth-616 and Earth-1610 careen toward a collision, it emerges that a way to avoid the incursion is to destroy one of the earths. This saves the other as well as both their respective universes. Thanos and The Maker, among the best alternate reality versions of Mr. Fantastic in Marvel Comics, plot to destroy Earth-616 to save theirs.
This complication likely arises in the MCU, though it seems that incursions arise simply from people crossing over from one universe to another. One universe destroys the other, rather than obliterating both as in the comics.
Battleworld
As the multiverse collapses, Doctor Doom, along with Doctor Strange and Molecule Man, discover The Beyonders initiated the incursions. In a desperate attempt to save existence, Doom kills The Beyonders and steals their powers. He then consolidates the multiverse's remaining vestiges into a single reality, Battleworld.
Doom, easily among the most powerful cosmic beings in the Marvel Universe at this point, installs himself as God Emperor on Battleworld, organizing reality as he sees fit. The MCU positions Kang as the big bad in The Multiverse Saga, but Doom could emerge as its unlikely hero, as he does in the comics.
Different Domains
Doom organizes Battleworld into different domains, each with its own provincial ruler called a baron. Most barons served as major superheroes or supervillains in their previous realities, with each best suited for their realm. She-Hulk protected the Warzone along with A-Force, Captain Britain protected New Avalon, and Khonshu, among the most powerful Heliopolitan gods in the comics, reigned over Egyptia.
This offers enormous possibilities for the MCU that a single movie likely can't contain. Numerous mini-series and one-shots spun off from the main Secret Wars title, and live-action potentially does the same with streaming series that showcase different domains.
Secret Wars Redux
The 2015 Secret Wars crossover takes its name and several elements from the original 1985 comic book mini-series, among the most important Marvel Comics events ever. The 1985 storyline brought together all of Marvel's key superheroes and villains for the first time, with The Beyonder depositing them all on Battleworld and forcing them to fight.
Doctor Doom played a large role in this storyline as well, ultimately fighting The Beyonder and taking command of the villains, including Kang The Conqueror. Doom orders Ultron to kill Kang for his insolence, which Ultron does.
Infinite Variants
The greatest potential Secret Wars presents for the MCU lies in bringing together endless variants. This series scrambled variants of major characters from different realities together and ultimately brought some to the main Marvel Universe once it was restored. This includes Miles Morales, who left behind Earth-1610 for 616.
The MCU already provided a preview of how this works in Spider-Man: No Way Home and Doctor Strange in the Multiverse of Madness, but the live-action contains the potential to take things to an unimaginable level, bringing in characters from every extant Marvel movie or television franchise.
Thor Corps
The Thor Corps represents a great example of what Secret Wars potentially means for the MCU. Doctor Doom uses the Thor Corps, an army of Thor variants from across the multiverse, to police Battleworld. They include many powerful Thor variants, including Jane Foster, who could return in live-action through this unique roster.
Jane Foster serves a key role in the story, as she proves instrumental in convincing the Thor Corps that Doom's proclamations about their origins and Battleworld's are merely self-serving lies.
The Life Boats
As the universe collapses, Mr. Fantastic instigates a last-ditch effort of his own. He creates lifeboats to protect people as the universe unravels with the hopes of finding a way to fix things later. Only one lifeboat appears to survive, containing Mr. Fantastic, Spider-Man, Captain Marvel, and others, which then beaches on Battleworld sometime later.
Given the Fantastic Four movie lands roughly a year before the Secret Wars one, the MCU Reed Richards may play a similar role in the live-action storyline.
Rebooting The Universe
Once Mr. Fantastic discovers what Doom did, including forcing The Invisible Woman to become his wife, a battle for the ages commences. The decades-old rivalry between the two characters informs an epic struggle that leads ultimately to Molecule Man transferring the Beyonders' power to Richards. He uses it to restore the entire Marvel multiverse.
This mission takes the Fantastic Four away from Earth-616 for several years, and out of the comics. Their disappearance occurred in large measure because of movie rights concerns involving both the FF and X-Men. Now, ironically, the Fantastic Four return to prominence in live-action in the same story that exiled them in the comics.