The cast of Avengers: Doomsday is a massive roster of superheroes, with a mix of established MCU characters as well as iconic favorites from other franchises. The fifth Avengers movie will focus on the fight against Robert Downey Jr.'s Doctor Doom, while featuring various MCU teams. Along with MCU heroes like The New Avengers, Avengers: Doomsday will also be welcoming back several of the original X-Men actors.
While there are also some key names missing from the official announcement, there are sure to be some secret additions to come. One rumored bit of casting promises to bring back another legendary superhero actor. However, this returning character might have bigger implications for one of the most heartbreaking MCU storylines.

Tobey Maguire is reportedly the Spider-Man in Avengers: Doomsday
Various alleged "leaks" from Avengers: Doomsday have reported that Tobey Maguire will return as Peter Parker, aka Spider-Man, in Avengers: Doomsday. The reports suggest that Maguire will be donning a CGI suit in the upcoming movie. However, there is another interesting element to the rumors as they suggest Maguire will be the only Spider-Man in the movie.
Tom Holland was one noticeable name left off the massive list of Avengers: Doomsday cast members. Many fans felt that it was likely he would still appear, though with Spider-Man: Brand New Day premiering before Avengers: Doomsday, it could give some indication as to why he is absent from the team-up event.
The rumors are that Maguire will step in to bring back his older and seasoned Peter Parker, last seen in Spider-Man: No Way Home. With Avengers: Doomsday bringing all the MCU's multiverse storytelling to a climax, it is perfectly reasonable that Maguire's Spider-Man would be included. It is an exciting addition for fans, but Maguire's inclusion could mean more than just a fun cameo.

Maguire's Spider-Man could save Holland's Spider-Man
Spider-Man: Brand New Day looks to be another thrilling Spider-Man adventure, with Tom Holland returning, but it also has a tragic element to it. Spider-Man: No Way Home ended with Peter Parker making a sacrifice to save his universe from multiverse incursions by instructing Doctor Strange to cast a spell so that everyone forgets who Peter Parker is.
As the movie ends, Peter saved the day, but is now alone as MJ, Ned, and even Happy Hogan no longer remember him. It will be interesting to see how the fourth Spider-Man movie deals with that massive storyline, but it could be that Maguire's return is the key to setting things right for Peter Parker.
With another Peter Parker from another universe possibly entering the MCU, he could be the one who reminds the world that Peter and Spider-Man are one and the same. Perhaps Maguire's Peter will be enough to break the spell enough that MJ or one of Peter's other loved ones gets some of those memories back.
At the very least, Maguire's Peter may be someone who knows Holland's Peter is Spider-Man. While Strange's spell affected the universe of the MCU, there is no indication that it would have impacted the other Spider-Man figures across the multiverse. Maguire could become the only one who knows this secret and be able to offer him some guidance in his lonely existence.
While it is still unconfirmed that Maguire will appear in Avengers: Doomsday, the possibility just gives another reason to be excited about the movie. It will remain to be seen how his appearance might work into the larger MCU, but hopefully, he will be given a storyline befitting his iconic status.
