The Fantastic Four franchise has consistently been a hit-and-miss affair for Marvel Studios. Now that Disney has confirmed its plans to integrate the world's first superhero family into the billion-dollar juggernaut known as the Marvel Cinematic Universe, the main villain in the upcoming reboot is rumored to be one of Marvel's biggest baddies.

If we're to believe the latest scoop from the reliable entertainment news leaker, @MyTimeToShineH, the Fantastic Four will be going up against the Devourer of Worlds, Galactus, come 2025, and an actor has already been cast for the role.
While many comic-book fans would have expected the cosmic entity to make his appearance in the MCU as the final boss of Phase 6, it makes sense that he would be the main villain in the reboot. In the 2007 film, Fantastic Four: Rise of the Silver Surfer, we learn that the Silver Surfer was working for Galactus all along. Given that the Silver Surfer is reportedly going to make his debut before the reboot is released in theaters, his appearance would set the stage for the advent of Galactus.
Comic book readers are well familiar with Galactus, the cosmic entity that consumes planets to sustain his life force. Unlike standard villains, Galactus operates without regard to the morality and judgments of mortal beings. Through consuming planets, Galactus embodies a living force of nature whose existence is necessary to correct the imbalances between the conceptual entities of Eternity and Death.
While most MCU superheroes oppose him due to the small-scale devastation he causes, what they fail to see are the large-scale issues that necessitate Galactus in the first place. Without him, life in other universes would cease to exist.
It would be interesting to see how Marvel would set up Galactus as a key villain in Phase 6. Kevin Feige has announced that Phase 6 will end with Avengers: The Kang Dynasty and Avengers: Secret Wars. Kang the Conqueror will take center stage in the former, while The Beyonder is reputed to be the main villain in Secret Wars. With all this in mind, it's likely that Galactus will be the next Thanos-level threat after Kang.
Ultimately, whether Galactus serves as the primary antagonist or not, a strong Fantastic Four reboot is all fans want. Adam Driver is reportedly the front-runner for the Reed Richards role, which, if accurate, would be the ideal casting decision.
Who knows? Maybe we'll get to see Liam Neeson as Galactus and Adam Driver as Reed Richards in theaters on February 14, 2025.