end of Marvel Studios' Infinity Saga. With the multiverse concept becoming highly popular in various franchises, it was only a matter of time before Marvel began to utilize it too. Throughout some of their latest movies and TV shows, the MCU has had some major fun moments allowing alternative takes on popular heroes and villains.
Following the big uniting of three Peter Parkers in Spider-Man: No Way Home, Doctor Strange in the Multiverse of Madness kept the multiverse ball rolling. One of the big central elements of the Doctor Strange sequel was the introduction of the Marvel group the Illuminati, and while it wasn't the Earth-616 version of the team, the film did give audience a taste of the iconic group. One of the major to be featured was none other than Reed Richards himself, with Krasinski being the first actor to portray Mr. Fantastic in the MCU.
A primary reason it became such a huge moment for Doctor Strange in the Multiverse of Madness to feature Krasinski was that he has been a major fan-cast idea for years, and it clearly got enough traction to show up on Marvel's radar. In the official Doctor Strange in the Multiverse of Madness audio commentary (via CBR), director Sam Raimi opens up on The Office star taking on the popular Fantastic Four hero. Raimi shares how Feige was the one to make it happen, stating the following:
It's so funny that [Marvel Studios president Kevin Feige] cast John because the fans had a dream of who the perfect Reed Richards would be. And because this is an alternate universe, I think Kevin said, 'Let's make that dream come true.' I've always really enjoyed all of his performances.
Krasinski being tapped as Reed Richards was just one of several Illuminati that Doctor Strange in the Multiverse of Madness featured during Stephen's visit to the other reality. This variation of the team featured variant versions of Hayley Atwell as Peggy Carter/Captain Carter, Sir Patrick Stewart as Charles Xavier/Professor X, Anson Mount as Black Bolt, and Lashana Lynch as Maria Rambeau, who operated as the Captain Marvel of this world. The team was quickly taken out of commission, however, as the Scarlet Witch murdered every single one of them with relative ease.
While Krasinski's fan-casting was embraced in Doctor Strange in the Multiverse of Madness, it doesn't necessarily mean Earth-616 will have the actor back in the role. Through the MCU's concept of the multiverse, variants don't always look the same. Spider-Man: No Way Home was the biggest example, by having Tom Holland, Andrew Garfield, and Tobey Maguire all operate as the Spider-Man of their respective universes. While Marvel Studios has an MCU Fantastic Four reboot in the works, Doctor Strange in the Multiverse of Madness didn't determine if Krasinski will play the Earth-616 variant of Reed Richards. Until further notice, Doctor Strange in the Multiverse of Madness will be the only MCU film to feature Krasinski as Mr. Fantastic.
Source: Doctor Strange 2 Official Commentary (via CBR)
