At San Diego Comic-Con, Marvel announced that Avengers: Secret Wars is set to come out in 2025. While many are excited to finally see the legendary 1984 event comic arrive on the big screen, there are many crucial pieces still missing from the Marvel Cinematic Universe that must make it onto the big screen if the adaptation is to capture the important events of the original comic. Some of those pieces are primed to appear in upcoming projects; others are still missing.

Secret Wars was one of the very first "event comics," or massive, company-wide crossovers involving various comic series interacting in a single narrative that changes the universe's status quo through a conflict with an enemy powerful enough to necessitate the presence of multiple heroes. Infinity War, Civil War and the upcoming Secret Invasion are examples of such event comics that have been adapted into MCU films. The 1984 comic involved a powerful being known as the Beyonder assembling a collection of earth-bound heroes and villains on "Battle World" to fight and prove whether good or evil is truly the stronger force. While many of those heroes and villains already exist in the MCU (such as the Hulk, James Rhodes, Spider-Man, Sam Wilson as Captain America, Monica Rambeau, Thor, Hawkeye, She-Hulk, the Wasp; villains Titania, Ultron and the Wrecking Crew; and alternate universe versions of Dr. Octopus and the Lizard), many of the most important players of the comic storyline are yet to appear on film.

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The Fantastic Four Comes With the Event's Protagonist-Antagonist

Fantastic Four the Thing, Mister Fantastic, Invisible Woman, and Human Torch in the Negative Zone

The first key players of the original comic still missing in the MCU are the long-awaited Fantastic Four and their nemesis, Doctor Doom. Doctor Strange in the Multiverse of Madness did provide a brief appearance by Mr. Fantastic, but as a member of the multiversal Illuminati, not a resident of the main MCU continuity. Dr. Doom is the centerpiece of the original comic, the great mastermind among the villains who succeeds in snatching ultimate power for himself and proves the unexpected final antagonist for the assembled heroes. Without his inclusion in the adaptation or that of his quartet of nemeses, the story will only be half adapted.

The Main Source of Inter-Hero Conflict: The X-Men

The long-awaited X-Men must be plausibly integrated with the Avengers cast. The X-Men and their arch-antagonist Magneto carry the bulk of the emotional drama between the heroes in Secret Wars, and, without their complex relationship with the Avengers, the film version will lack one of the comic's main story threads -- in particular, the ambiguous nature of what the Beyonder, the all-powerful instigator of the conflict, considers good or evil, thanks to Magneto's inclusion on the heroes' side.

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The Most Iconic Piece's Unlikely Source: Spider-Woman

Spider-Man's new black suit from Secret Wars with Julia Carpenter as Spider-Woman split image

Though in theory, the infamous Black Costume Spider-Man storyline has the potential to occur regardless, the original Secret Wars introduced the future Venom symbiote via the interactions between Spider-Man and Spider-Woman. The latter, aka Julia Carpenter, was a well-established character by the time the 1984 story was released, and her black threads provided what in Peter Parker's mind appeared to be the reason for his brand-new costume -- unaware of the truth behind its nature. Without her presence in the MCU, the motivation behind the costume's original creation may be lacking. Finally, on the villains' side, key players such as Enchantress, Molecule Man, Absorbing Man and Volcana are also still missing from the MCU's lineup.

While the MCU can hypothetically introduce at least the major players still absent in three years (the upcoming Fantastic Four film, a future Thor film for Enchantress, and the possibility of the X-Men), it is possibly a bit too soon to successfully pull off this storyline. It may be better suited for a few more years down the line when those key players have become integrated parts of the franchise in whom fans can put as much passionate investment as they traditionally had in heroes such as Iron Man and Captain America. The MCU has set a big task for itself, to understate, and it may be better to achieve it slowly than rush a lesser version.