Henry Cavill rose to international fame playing Superman in the DCEU; in fact, his movie Man of Steel pretty much kickstarted the whole thing, serving as the foundation of the universe. His Superman remains divisive with critics and audiences, leading many to believe he might not get another chance to play the Last Son of Krypton.
Who knows what the struggling DCEU will do in the future, but even if he doesn't get to put on the cape again, Cavill could still be a superhero. Indeed, there are multiple characters over in the far more successful MCU that Cavill could play and excel in, delighting millions of fans worldwide.
Jack Of Hearts
Jack of Hearts is far from the most well-known comic book character, but he's one of the most underrated Marvel heroes nonetheless. Jack Hart was the son of a human man and a Contraxian woman who, unable to control his powers, built a suit to keep himself from self-destructing. They eventually got out of his control, and he left Earth, exploding alone in space.
The tragedy of the Jack of Hearts would make for a compelling big-screen story in the next Avengers movie, and Cavill could really sink his teeth into it. Furthermore, Jack of Hearts would be a one-off role, meaning Cavill could still return to the DCEU in the future.
Colossus
Fans have long awaited the X-Men's arrival into the MCU; and rumors swirl about their appearance in the Multiverse of Madness. Still, the X-Men are a foundation of the Marvel universe as a whole, and they will surely play a crucial role in Phase 5 and going forward.
Colossus might be one of the most underrated members of the team. He isn't as famous as, say, Cyclops or Wolverine, but he's a crucial part of the mutant squad. Colossus also has a rich backstory that ties him to other crucial Marvel characters, including his sister, Magik. Cavill certainly has the impressive physique to play a convincing Colossus, and having a name-actor in the role would increase Colossus' importance within the X-Men.
Cyclops
Another of the X-Men, Cyclops will surely play a pivotal role in the MCU mutant world. Scott Summers is one of the X-Men's best leaders, famous for his complicated family history and iconic romances with Jean Grey and Emma Frost.
The Fox X-Men movies did a huge disservice to the character, basically relegating him to the background in favor of Wolverine. The MCU has the chance to rectify that mistake by placing Cyclops front and center as the team's best tactician. Cavill would be an intriguing choice for the role, mixing the stoic heroism he displays in The Witcher with the all-American wholesomeness he brought to Superman, thus creating the definitive version of Cyclops.
Nova
The original Nova, Richard Rider, gets his fabulous powers from the Nova Force. He can fly and has superhuman strength, durability, and speed, along with the ability to absorb energy and re-release it as beams and pulses.
So far, the cosmic corner of the MCU universe has been anchored by Star-Lord and his Guardians of the Galaxy. However, the Guardians are heading for their last vow with the upcoming third film in their franchise, leaving an empty spot that Nova and the Nova Corps can fill. Cavill would be great in the role, bringing the same charm he displayed in The Man from U.N.C.L.E. to Nova's distinct cocky personality.
Mister Sinister
The X-Men have some of the Marvel pantheon's best and most complex villains, and Mister Sinister is the perfect example. Born Nathaniel Essex in Victorian London, Sinister undergoes genetic engineering courtesy of Apocalypse, becoming immortal and gaining slight telepathic abilities and complete control over his body on a molecular level.
Unlike other X-Men villains, Sinister has never been used in live-action. He has the potential to be a major threat for the MCU as a whole, and Cavill would be an incredible choice for the part. Not only is he physically imposing and British, but he has a distinctive quality that makes him menacing without saying a word. Sinister's chalk-white skin and red eyes would also allow Cavill to disappear into the role.
Captain Britain
Created in 1976, Captain Britain was originally meant to be the British counterpart for Captain America. In keeping with his British origin, the character received mystical powers from the legendary wizard Merlyn, including superhuman strength, flight, and various weapons, mainly a quarterstaff.
Captain Britain is the most common fan-casting for Cavill. Indeed, numerous pieces of fanart depict the actor as the character, with Cavill himself expressing interest in the role. Only time will tell if it will come to pass, but the pieces are all set.
Galactus
Galactus is perhaps one of the most iconic villains in comic book history. Although he's mainly associated with the Fantastic Four, Galactus has also fought numerous other Marvel heroes, often threatening the entire universe with his vast powers.
Because Cavill is already closely associated with a hero, it might be best he played a villain in the MCU. Comic book fans know Galactus is one of the most intriguing figures in Marvel lore, a perpetually hungry cosmic force with a rich backstory that remains largely unexplored in live-action. Galactus also has the potential to be a Thanos-level threat for Phase 5 of the MCU, meaning Cavill would be in it for the long run.
Hercules
Hercules is one of those characters only comic book fans know are part of the Avengers. Based on the mythological character of the same name, Hercules debuted during the Silver Age and quickly became part of the Avengers. In keeping with his mythological origins, Hercules is the strongest of the Olympian beings.
Fans already know Zeus is coming to the MCU, played by Russell Crowe in the upcoming Thor: Love and Thunder. Having Cavill once again play Crowe's overpowered son might be a bit too on-the-nose, but it would be worth it. Cavill already played a character from Greek mythology, Theseus, in Tarsem Singh's underrated 2011 film Immortals and has the physicality needed to convincingly portray an Olympian. Plus, who wouldn't want to see Cavill batting alongside Chris Hemsworth's Thor?
Sentry
Robert "Bob" Reynolds, better known as Sentry, might be one of the most overpowered characters in Marvel comics. The true nature and extent of his abilities remain unknown, as is their origin. Initially, the Sentry's powers derived from an enhanced version of the Super Serum said to be a hundred thousand times stronger than Captain America's. However, later stories, like the Age of Sentry mini-series, claim the Sentry is an intergalactic sentient life force.
Sentry is Marvel's equivalent to Superman in many ways, making perfect sense for Cavill to play him. With Marvel Cosmic becoming such a prominent part of the MCU, multiple intergalactic characters will surely keep appearing, and Sentry would be a powerful ally for future conflicts. It's unlikely he would ever warrant a solo movie, but Cavill could pull a Mark Ruffalo and play a supporting role across multiple films.
Doctor Doom
If Mission Impossible: Fallout proved anything is that Cavill excels in villainous roles. His stoic demeanor and intimidating build would make him the perfect choice to bring nearly any comic book villain to life, and there's arguably no better villain in Marvel than Doctor Victor von Doom.
Doom is not only one of the most intelligent figures of the Marvel universe and the archenemy of the Fantastic Four but also one of the mightiest beings in comic books. He is a strong candidate for being a Thanos-level antagonist after Kang's tenure. Playing an overtly antagonistic role would also provide a stark contrast from Cavill's previous comic book character, meaning the actor could someday return to the Superman role without creating any conflict.