There are many powerful Avengers villains from Marvel Comics that haven’t yet appeared in the MCU, but may have already been set up for the future.

Some of Marvel Comics’ most powerful Avengers villains might have already been set up in the MCU. Marvel Studios’ Avengers formed in 2012’s eponymous The Avengers to battle the God of Mischief Loki, who had staged an attack on New York City. The MCU’s original Avengers team comprised Iron Man, Captain America, Black Widow, Hawkeye, the Hulk and Thor, but with each new Avengers project, the roster has grown and increased in strength. As the team has become stronger, though, so have their villains, but some of the Avengers’ most formidable Marvel Comics foes haven’t yet appeared in the MCU.

Throughout their career as the MCU’s premiere superhero team, the Avengers have battled a variety of villains, both Earth-based and otherworldly. The Avengers saw the titular team battle Loki and his Chitauri army, Avengers: Age of Ultron brought them in conflict with the titular artificial intelligence, Ultron, and Captain America: Civil War saw them battle each other thanks to the machinations of Baron Zemo. The Avengers’ most significant villain in the MCU, however, has been Infinity War and Endgame’s Thanos, but some of the Avengers’ unused villains from Marvel Comics could even rival the power of the Mad Titan himself.

10. Eternals May Have Set Up The MCU’s Enclave

Marvel Comics’ debuted the Enclave, a group of dictatorially-minded scientists, back in 1967’s Fantastic Four #66, and while the Enclave are primarily an enemy of the Fantastic Four, they have also battled the Avengers. Founded by scientists Jerome Hamilton, Maris Morlak, Wladyslav Shinski and Carlo Zota, the Enclave sought advanced technology capable of establishing a benevolent dictatorship that they would lead. In Marvel Comics, the Enclave was responsible for the creation of Adam Warlock, and battled the Hulk, Doctor Strange and Spider-Man while trying to conquer Earth and the Inhumans’ home city of Attilan and the mutant nation of Genosha.

How The MCU Has Set Up The Enclave

While Adam Warlock’s origins in the MCU have been changed to make him a creation of the High Evolutionary, the Enclave has been set up elsewhere. 2021’s Eternals actually introduced the perfect way for Marvel Studios to bring the Enclave into the MCU. In Marvel Comics, the Enclave uses stolen Deviant technology to advance its cause, which means that the Enclave could debut in a potential Eternals 2, perhaps even basing themselves on the body of the dead Celestial Tiamut.

9. HAMMER Could Form After The Events Of Secret Invasion & The Marvels

Following Marvel Comics’ Secret Invasion event in 2008, Norman Osborn was promoted to Director of SHIELD, but used his position to dismantle the espionage agency and set up HAMMER in its place. Norman Osborn’s reign of HAMMER marked a dark period for the Marvel Universe, as he sought the information of every superhero listed in the Superhuman Registration Act, and embarked on the Siege of Asgard, with the organization later becoming a nefarious group once the United States government apparently dissolved it. Osborn even established a new Avengers team within HAMMER, but these weren’t the heroes everyone knew and loved.

How The MCU Has Set Up HAMMER

Marvel Studios’ Secret Invasion perfectly laid the foundations for HAMMER to emerge in the MCU, as President Ritson declared war on all Earth-based extraterrestrials. This puts the Skrull refugees and the Asgardians in New Asgard in danger, and could lead to an adaptation of Marvel Comics’ Siege event. This may have only been exacerbated by more Skrulls seeking refuge on Earth in The Marvels, so perhaps the founding of HAMMER could add weight and meaning to these disappointing MCU installments.

8. The Dark Avengers Have Been Teased For The MCU’s Future

While HAMMER could play a key role in the MCU’s future, the organization’s own Avengers team may have also been teased. After assuming control of HAMMER, Norman Osborn established the Dark Avengers team, comprising twisted and corrupted supervillains and antiheroes disguised as heroes who often took aggressive and violent actions to complete their missions. The Dark Avengers had a huge part to play during the Siege of Asgard, and an even darker team was later established with backing from HYDRA and AIM. Osborn even established the Dark X-Men, giving Marvel Comics’ villains the center-stage for some intense and dramatic stories.

How The MCU Has Set Up The Dark Avengers

Julia Louis-Dreyfus’ debut in The Falcon and the Winter Soldier as Contessa Valentina Allegra de Fontaine, a.k.a. Marvel Comics’ Madame Hydra, led some to speculate that she could be forming the Dark Avengers. Her team has since been revealed to be the MCU’s Thunderbolts team. However, the Dark Avengers may also have a role in the MCU’s future, particularly with powerful members, including the Sentry, Venom, Wolverine (and potentially his disgruntled son, Daken) and Bullseye, set to be introduced to the MCU very soon.

7. The Beyonders Could Be Introduced Before Avengers: Secret Wars

Years after the Beyonder took the role of the mastermind behind Marvel Comics’ Secret Wars event in 1984, the powerful villain was revealed to be a child of the Beyonder race, with the Beyonders playing a huge role in 2015’s Secret Wars. These higher-dimensional beings were responsible for the incursions that ravaged the multiverse, but they had their power stolen by the Molecule Man and Doctor Doom, allowing the latter to establish Battleworld in the wake of the multiverse’s destruction. The Beyonders’ power is incomprehensible, so it would be fantastic to see these otherworldly villains appear in the MCU’s future.

How The MCU Has Set Up The Beyonders

While the Beyonders haven’t actually been set up properly in the MCU just yet, it’s very possible they could soon make their theatrical debut. Avengers: Secret Wars is scheduled for release in 2027, and is expected to be adapted from 2015’s Secret Wars event, with incursions playing a key role. This means that any number of MCU heroes could assume the powers of the Beyonders and establish Battleworld, and this honor could even fall on Doctor Doom, if the iconic Marvel Comics villain is introduced in the MCU’s Phase 6.

6. The Legion Of The Unliving Has Connections To Kang The Conqueror

Six different versions of the Legion of the Unliving have been introduced in Marvel Comics, but the first team comprised deceased heroes and villains who had been plucked out of time to battle the Avengers. Five versions of the undead team fought the Avengers, while the sixth was established by Colonel Shadow for his vampire civil war. The Legion of the Unliving featured the likes of Wonder Man, Captain Marvel, the Green Goblin, Red Guardian and the Swordsman, pulled out of time in the moments before their deaths to fight the Avengers – who had sometimes been their former allies.

How The MCU Has Set Up The Legion Of The Unliving

The Legion of the Unliving has one clear connection in the MCU that could be important to 2026’s Avengers 5, as the team was regularly formed by Kang the Conqueror and his variant, Immortus. Jonathan Majors won’t be returning to portray Kang in the MCU’s future, but the multiversal villain could be recast, allowing him to establish his own Avengers team. This would be a fantastic defense against the MCU’s new Avengers, and could mark the return of some of the MCU’s deceased superheroes and villains.

5. The Masters Of Evil Were Marvel Comics’ First Thunderbolts

While the Dark Avengers could be a potential replacement for the Thunderbolts in the MCU, Marvel Studios could also introduce the Masters of Evil to battle the Avengers. In Marvel Comics, Baron Helmut Zemo’s Masters of Evil disguised themselves as the first Thunderbolts team, masquerading as heroes in the wake of the Avengers’ apparent deaths, but by functioning as heroes, many of the villains on the team began to change their ways. This evolution from villain to hero would be fantastic to see in the MCU, so it would be brilliant for the Masters of Evil to be introduced soon.

How The MCU Has Set Up The Masters Of Evil

Marvel Studios seems to be introducing the Thunderbolts team in the MCU’s Phase 5 already operating as the Thunderbolts, rather than debuting the Masters of Evil. However, this may not be the only Thunderbolts team forming in the MCU, as Daniel Brühl’s Baron Zemo could easily bring together his own team from within the confines of the Raft prison. This could form the Masters of Evil in the MCU, who could be formidable opponents to both the Avengers and the Thunderbolts.

4. Serpent Society Has Been Rumored For Captain America: Brave New World

Marvel Comics’ Serpent Society has been around since 1985’s Captain America #310, and has been a persistent threat to both Steve Rogers and Sam Wilson’s Captain America since then. Comprising snake-themed villains, including Diamondback, Sidewinder, Bushmaster, Rattler and Anaconda, among others, the Serpent Society’s members acted as protection for each other, and regularly took jobs for criminal organizations such as HYDRA, Kingpin, AIM and the Maggia. The gimmicky nature of the Serpent Society may make it difficult for them to be accurately adapted into the live-action MCU.

How The MCU Has Set Up The Serpent Society

Speculation previously suggested that the Serpent Society was set to make its MCU debut in 2025’s Captain America: Brave New World. The Phase 5 project will be the first theatrical release focused on Sam Wilson’s new Captain America, so the Serpent Society would have fit in perfectly. Although more recent rumors suggest the Serpent Society may have been removed from Brave New World, the group would still be a fantastic addition to Anthony Mackie’s upcoming big-screen debut as Captain America.

3. Marvel Studios Could Finally Adapt The Sinister Six For Tom Holland’s Spider-Man

Spider-Man’s rogues gallery of villains is one of Marvel Comics’ most impressive, and among them is the Sinister Six, a superteam of iconic Spider-Man villains who first teamed up in 1964’s The Amazing Spider-Man Annual #1. The Sinister Six hoped that, by combining their efforts, they could have the power to defeat Peter Parker, but the wall-crawler has bested the supervillain team many times in the years since. Originally formed of Doctor Octopus, Kraven the Hunter, Electro, Vulture, Mysterio and Sandman, the line-up of the Sinister Six has changed over the years, and the MCU’s version could be very different.

How The MCU Has Set Up The Sinister Six

2021’s Spider-Man: No Way Home almost introduced an iteration of the Sinister Six into the MCU, as Tom Holland’s Peter Parker fought five multiversal villains. There has also been a Sinister Six project in the works for Sony’s Spider-Man Universe for several years, so it’s possible Marvel Studios and Sony could work to bring a true Sinister Six into the MCU. This could include iconic MCU villains such as Mysterio and the Vulture, but details of this potential team remain to be seen.

2.The Brotherhood Of Mutants Can Bring Together The Avengers & The X-Men

While Marvel Comics’ Professor X formed the X-Men to try and strive for a peaceful existence for both humanity and mutants, Magneto founded the Brotherhood of Mutants to seek his own goals. Magneto’s Brotherhood of Mutants are devoted to mutant superiority over humanity, which brings the group into conflict with the X-Men on many occasions. The Brotherhood of Mutants has gone through many changes, but Magneto is the group’s most recognizable leader. With the MCU’s X-Men project in development, the Brotherhood of Mutants’ debut may be just around the corner.

How The MCU Has Set Up The Brotherhood Of Mutants

Despite being more often depicted as adversaries to the X-Men, Magneto’s Brotherhood of Mutants have also battled the Avengers several times, making them a significant potential threat in the MCU. Marvel Studios’ introduction of mutants has been slow since Disney’s acquisition of 20th Century Fox was finalized in 2019. Nevertheless, Deadpool & Wolverine and the upcoming X-Men reboot will introduce mutants to the MCU en masse, and the Brotherhood of Mutants would be an excellent antithesis to the X-Men.

1. Doctor Doom Has Been Heavily Rumored For The MCU

Doctor Doom is one of Marvel Comics’ most recognizable and powerful villains, not just for the Avengers, but for practically every superhero in the Marvel Universe. This makes him a clear candidate to be introduced to the MCU, as the ruler of Latveria could be a significant threat for years to come. Doctor Doom is primarily a foe of the Fantastic Four, having studied alongside Reed Richards, but has also battled the likes of Spider-Man, Iron Man, the Black Panther, the X-Men and the complete Avengers team.

How The MCU Has Set Up Doctor Doom

Doctor Doom has been heavily rumored to be debuting in the MCU very soon, potentially in 2025’s The Fantastic Four. This could set him up as a slow-burning villain, allowing him to stick around for many years to come. Doctor Doom has a huge part to play in Marvel Comics’ Secret Wars event in 2015, so he could be introduced as the primary antagonist of Avengers: Secret Wars in the MCU, taking over from Kang the Conqueror, should the powerful Avengers villain be replaced.