How Excluding The X-Men & The FF Affected The MCU — Part 2
In the original “Civil War” arc in the mainstream comic universe, the X-Men and the Fantastic Four played crucial roles in the story development.

The Marvel Cinematic Universe (MCU) quickly adapted major storybook arcs for its films but was required to modify their stories for legal reasons while keeping true to the main plots. The X-Men and the Fantastic Four played fundamental roles in those major story arcs but they couldn’t be used in the MCU because their character rights were still owned by 21st Century Fox which stems from the licensing deal in the 1990s.
This is why we haven’t seen any semblance until Doctor Strange in the Multiverse of Madness where Professor X and Mr. Fantastic make their MCU debut. The characters' rights to Maximoff Twins are a loophole that Marvel Studios and 21st Century Fox took advantage of which is why you see two different versions of Pietro Maximoff.
Without the X-Men or the Fantastic Four, it sucked the flavor of the MCU’s version of the major story arcs.

Captain America: Civil War
In the 2016 film, the chain of events begins with a small group of Avengers (Captain America, Black Widow, Falcon, and Scarlet Witch) thwarting Crossbones from stealing a biological weapon. This ends up with Crossbones blowing himself up and trying to take the Avengers with him. Scarlet Witch has the good intentions to use her powers to send the explosion elsewhere but it destroys a nearby building and kills several Wakandan humanitarian aid workers.
The explosion also claims the life of King T’Chaka of Wakanda, the son of T’Challa, which sets up the 2018 film Black Panther.
Everything is FUBAR for the Avengers and the United Nations (U.N.) passes the Sokovia Accords which is the MCU’s version of the Superhuman Registration Act (SHRA) which has a ripple effect (watch Marvel’s Jessica Jones and Spider-Man: No Way Home). Tony Stark aka Iron Man supports the measure because of what happened in Avengers: Age of Ultron and Steve Rogers opposes the measure because he doesn’t trust the judgement of politicians.
This leads to a showdown between Iron Man and Captain America’s factions. It is where Peter Parker aka Spider-Man, played by Tom Holland, makes his MCU debut via a partnership with Sony Entertainment Pictures.
James Buchanan Barnes, who reappeared as the Winter Soldier in Captain America: The Winter Soldier, also plays a role in the rift between Iron Man and Captain America.
Helmut Zemo, who makes his MCU debut in the film, sparked this civil war out of anger against the Avengers for what happened to Sokovia (watch Avengers: Age of Ultron).

Marvel Comics “Civil War”
In the original comic universe, Universe 616, Stamford, Connecticut, is ground zero for the chain of events leading to the “Civil War.” The New Warriors, who have yet to make an MCU appearance, are in dire financial straits. They receive a financial lifeline if they agree to be stars of a reality TV show.
The New Warriors battle a group of villains and Nitro, a member of the latter, unleashes his power (self-detonation and regeneration). Speedball is the only surviving member of the New Warriors group present in Stamford. The blast also claimed the lives of 600 people including school children which led to repercussions.
Because children were killed in the blast, public opinion has turned against superhumans. The United States Congress passed the “Superhuman Registration Act” (SHRA) with the guidance of Iron Man. It requires everyone with superhuman abilities to register with the United States government. There’s more, though, it also the enlistment and training of all aspiring superheroes. If you want to be a superhero, you have to work for the government.
Both criteria have consequences.
The first criterion makes their identities public. If your identity is public, everyone important person in your life becomes a target.
The second criterion ties the hands of the superheroes because of the argument between “legality” and “morality.” You want to do the right thing but you risk violating provisions of the SHRA. The U.S. Government also gets to decide what superheroes get to do.
Imagine the MAGA Republicans having the legal authority to dictate what superheroes can and cannot do…
For unrevealed reasons, Doctor Strange is exempt from the SHRA. Iron Man is pro-SHRA and is joined by Mr. Fantastic and She-Hulk. Captain America is anti-SHRA and is joined by figures such as Iron Fist (who disguises himself as Daredevil), Falcon, and Luke Cage.
Sue Richards, famously known as the Invisible Woman, is originally pro-SHRA but changes her mind when Ragnarok, a Thor clone made by Mr. Fantastic, kills Goliath. Spider-Man is initially supportive of the SHRA, which leads to a legal battle with J. Jonah Jameson, but has a major change of heart that causes him to side with Captain America.
Benjamin Grimm aka “The Thing” becomes disgusted with how things have turned out and heads to France.
The X-Men chose neutrality because the “House of M” event led to a decimation where most of the mutant population was depowered leaving only 198 mutants retaining their abilities. Bishop is pro-SHRA because he fears mutant-kind will be wiped out if it doesn’t comply with the SHRA. The Xavier Institute becomes a “relocation camp” patrolled by Sentinel Squad O*N*E* on a regular basis.

Storm, who married T’Challa and became the Queen of Wakanda, chooses to leave the United States for Wakanda, though the U.S. Government tries to punish her.
S.H.I.E.L.D is tasked with enforcing the SHRA and the mutants are tasked with policing themselves.
Wolverine chooses to side with Captain America but conducts his investigation where he learns that the corrupt leadership of Damage Control orchestrated the explosion. He learned that Nitro was supplied with the Mutant Growth Hormone (MGH) that increased the damage output and radius of the latter’s powers.
The event ends with the superhuman community accepting the SHRA. Superhumans who previously opposed the SHRA are granted amnesty if they either register or turn themselves in. Captain America is assassinated in the process and the mantle temporarily goes to Bucky Barnes. Since the events of the SHRA have affected their marriage, Mr. Fantastic and the Invisible Woman take time away from the team with Storm and Black Panther temporarily filling in.
Everything about the X-Men and the Fantastic Four franchises was crucial to the Civil War event. Since the MGH was originally discovered by Dr. Hank McCoy, who is also known as the X-Men member Beast, it’s part of the X-Men franchise, which meant only 21st Century Fox was allowed to use that plot device.
This is why the MCU and original comic book versions played out differently.
Stay tuned for Part 3 where I focus on Marvel Comics trying to kill off the mutants and have the Inhumans fill the void.