On Sunday, November 22nd, Izuku (Justin Briner), Bakugo (Clifford Chapin), and Shoto (David Matranga) wearing updated costumes, framed by the roman numeral three, and accompanied by the tagline, “He will meet 'The Three Musketeers'.” While it hasn’t officially been confirmed that a new MHA film is in the works, fans of the popular anime series began to speculate on social media about the potential plot of the film, with one theory hinting at the return of the series’ main villain, All For One (John Swasey).
The series creator Kohei Horikoshi mentioned in a statement in 2019 that My Hero Academia: Heroes Rising would probably be the final film in the franchise because he believed he couldn’t outdo Heroes Rising. After official sources released the mysterious teaser poster, it renewed hope for another animated film amongst the MHA fanbase. Among the theories fans proposed online, the “He” who is referred to in the sentence is likely a new villain that the “Three Musketeers”— Izuku, Bakugo, and Shoto— will face next. However, since both MHA movies featured climactic endings, with My Hero Academia: Two Heroes showing Izuku and All Might (Christopher Sabat) fighting side-by-side while Heroes Rising had Izuku temporarily One For All over to Bakugo, one way the third MHA film could raise the stakes would be to feature All For One, which appears to be implied within the teaser.
Based on the clue “He will meet 'The Three Musketeers,'” the poster suggests that the new MHA movie will feature All For One in some capacity. The term “Three Musketeers” has a deeper meaning within MHA, since the iconic motto from Alexandre Dumas’ novel The Three Musketeers, “One for all, all for one,” is also the name of Izuku and All For One’s “quirks” or superpowers, known as “One For All” and “All For One” respectively. With this in mind, the clue might be teasing that Izuku and All For One will meet for the first time in the new movie. While Izuku and All For One's meeting could entail their epic showdown foreshadowed during the season 2 episode “Listen Up!! A Tale From the Past,” the villain could alternatively be featured in the film on a smaller scale, detailing through flashbacks another mystery about All For One: his origins and rise to power.
Based on the trajectory of the MHA anime series, it would make perfect sense to have All For One appear within the next film. All For One disappeared from the anime series after he fought All Might at Kamino Ward in season 3 and was incarcerated at Tartarus. During the post-credits scene in the episode “End of the Beginning, Beginning of the End,” All For One states that All Might “missed his opportunity to vanish” in order to “help his student become independent”, a sacrifice All For One seems to have made for his pupil Shigaraki to evolve on his own. Since season 4 shows Shigaraki becoming an independent leader of the League of Villains, he essentially replaced All For One as the series’ main villain. With this in mind, All For One may no longer be relevant to the main anime/ manga timeline, making a standalone film the only solution for All For One to return without disturbing Shigaraki’s arc.
One flaw with this theory is the fact that the MHA movies technically aren't canon within the anime/manga series, since the events within the MHA movies are never referred to within the anime series and exist as standalone stories. If Izuku were to face the main villain All For One alongside class 1-A in the next film, it would be such a massive event within the franchise that it would be impossible for it to not have consequences on the main series. Alternatively, since Horikoshi was more involved in the making of Heroes Rising than the first film Two Heroes, his continued involvement in the possible My Hero Academia film might permit it to crossover into canon.
