Warning - The rest of this article contains spoilers for Doctor Strange in the Multiverse of Madness.
Earth-838. This corner of the MCU Multiverse is home to quite a few elements that are not (yet) present in the main Earth (Earth-616) explored in Marvel Studios' various projects. For starters, Earth-838 is home to not only mutants, and very likely by extension, the X-Men, but also to none other than Marvel's First Family: the Fantastic Four. While audiences don't end up meeting the whole FF team in Doctor Strange in the Multiverse of Madness, they are introduced to their leader, the smartest man alive, Dr. Reed Richards.
Of course, Reed doesn't last long after his debut in the film; he gets turned into string cheese by one Wanda Maximoff aka, Scarlet Witch. Indeed, none of the heroes met on Earth-838, save for one, last very long after Wanda enters the scene, as she brutally murders them one by one. But she was going through some stuff. Some Darkhold-influenced stuff. It's best not to get into it.
John Krasinski: The MCU's Main Mister Fantastic?
What is worth getting into in further detail, however, is Reed Richards. Of course, in Multiverse of Madness, the stretchy superhero is brought to life by actor John Krasinski. Does Krasinki playing the character sound familiar? It should if one follows the discussion surrounding the MCU. Fans have been clamoring for the Office alum to lend his talents to the father of the Fantastic Four since at least 2017. And with the release of the Doctor Strange sequel, it's finally happened.
But this Mister Fantastic is both from another reality and dead, which begs the question: Was Krasinski's casting meant as a one-off thing meant to appease the fanbase, or will the Jack Ryan star step into the role in the mainline MCU, likely starting with Marvel Studios' upcoming Fantastic Four movie?
For one, Krasinski is the right age to take on the character. Not to mention, he also has action franchise experience as the lead in Tom Clancy's Jack Ryan series on Amazon Prime.
Furthermore, judging by his all-too-brief performance in Doctor Strange 2, he's very much suited to the character, delivering his lines with an almost detached, holier-than-thou demeanor. Anyone who follows the Fantastic Four of the comic books will know that Reed Richards can be quite arrogant and oftentimes distracted by his scientific work and research, often to the detriment of the relationships he has with others.
Additionally, the very makeup of Earth-838's superhero roster would seem to suggest that Krasinski will carry forward to Earth-616. 838's Illuminati is composed of, save for Charles Xavier, characters played by the same actors who played the roles in the MCU or in-house Marvel productions. Peggy Carter is still Hayley Atwell, Maria Rambeau is still Lashana Lynch, and Anson Mount is still Black Bolt.
Is This Theory a Stretch?
With all this in mind, it's worth noting that joining the Marvel Cinematic Universe in a major role is a massive commitment for an actor. Most of the time, their requirements are not just to star in solo films but also to crossover into other characters' movies and participate in team-up movies. Perhaps Krasinski doesn't wish to sign away the next decade-plus to the Marvel machine? It would be quite understandably so.
So the question remains, was this just a piece of stunt casting? Hopefully not, although many fans have been very much persistent in their calls for John Krasinski's casting as Mister Fantastic. Let's hope that his appearance in Multiverse of Madness wasn't a one-and-done type of thing.
It warrants mentioning that many of the people who have been begging for the Jim Halpert actor to lead the Fantastic Four have also been very vocal about wanting Krasinski's real-life wife, Emily Blunt, to step into the transparent shoes of Sue Storm's Invisible Woman. Sue is Reed's teammate on the FF and also his wife.
Blunt, who has been up for MCU roles in the past, most famously that of Black Widow, stated in a 2021 interview that there have been no calls placed to her from the top brass at Marvel about her or her husband joining these movies. But one doesn't need to look any further than the most recent Marvel blockbuster for proof to the contrary of her claims.
Whatever the case may be, Kevin Feige and Marvel Studios will be in attendance at this year's San Diego Comic-Con as well as the Disney D23 convention. And with Fantastic Four reported to start filming in 2023, fans will very likely receive official word of who has been cast as the Marvel Cinematic Universe's First Family.