It is now known that the main role in «Avengers: Doomsday» will be taken over by Robert Downey Jr, however, details of further Marvel casting hint at another central character.
As insider Daniel Richtman notes (via LRM), it’s about Franklin Richards, for which they are looking for an actor aged 10-13 — and the terms state that the character will play a «leading role».
Franklin Richards — is the son of Reed Richards and Sue Storm, as well as a mutant capable of distorting reality. Previously, there were rumors that the character would appear in new «Fantastic Four» but will be depicted as a kid aged 3–4 years.
Earlier, Richtman wrote that Marvel considering Gwyneth Paltrow’s return to the role of Pepper Potts, although he clarified that he was not sure whether he had already had any conversations with her. This may seem like mere rumor or speculation — but remember that some of the preliminary ideas of the MCU, as outlined by journalists, have come true.
Josh Brolin also stated that is ready to reprise the role of Thanos in the new «Avengers»if Marvel offers «the right story». The return of his character seems even more realistic if we remember that «The Avengers: Secret Wars» will be based on the 2015 Marvel Comics storyline where different realities collide to form Battleworld (which effectively opens the door for characters from all over the multiverse to appear, even those who seem to have been defeated).
Recall that «Avengers: Doomsday» will be released in theaters on May 1, 2026, while «Avengers: Secret Wars» will debut on May 7, 2027 — both directed by the Russo brothers.