The next huge villain of the Avengers may be hiding in the MCU’s backyard. An all-new Avengers: Endgame theory has claimed that Bruce Banner/Hulk would be the next villain, but will appear as Maestro. The Maestro Hulk is a popular supervillain from an alternate future which is a mix of brain and brawn.
While posting to Reddit’s r/FanTheories, the user u/IAmTheDos argues about Hulk’s depiction in Endgame, and this sees Bruce Banner, and Hulk have earned harmony as Smart Hulk, which is inspired by Professor Hulk from the Marvel Comics lore. This has set up for Maestro as Banner who has “figuratively murdered the Hulk and stolen his body.”
The very merger of personalities had resulted in a Hulk who is “fairly happy/carefree,” and the shift in persona is different from a toddler-like Hulk as seen in the movie, Thor: Ragnarok.
The Reddit user then points to Hulk’s fun attitude as he jokes around when testing the concept of time travel on Ant-Man.
Because Hulk and Banner’s merger into a mood-changed Hulk had resulted in an all-new personality whose differences are noted by Black Widow and Captain America, the user has argued that Hulk’s power is now “affecting Banner’s mind like a psychoactive drug.”
This will “slowly corrupt his mind,” and will also transform Hulk into a Hulk that wages war on his allies.
The comic book storylines which could be adapted are “Future Imperfect,” where Maestro had originated as a Hulk driven mad by the effects of a world destroyed by Civil War II, borrowing from the Marvel Comics event that had seen Bruce Banner killed by Hawkeye, and “World War Hulk,” which had shown the fans Hulk return as a “World Breaker”.
Avengers co-director Joe Russo had said that the merger of the two personalities had been viewed as “the only natural progression” for the body-sharing the Other Guy and Banner:
“Banner reflects over that five-year period about ‘The two of us have been fighting over this host body for years, and we lost because we were fighting. It was selfish of us to fight over the host body,’” Russo had said.
“So the only natural progression forward for someone as intelligent as Banner to resolve the situation is, ‘Let’s merge ourselves. Let’s quit fighting over the host body and just merge.’”]