Marvel Studios hit San Diego Comic-Con hard this year by announcing the upcoming Phase 4 of the Marvel Cinematic Universe, which is something fans have been waiting a few years to see revealed. Earlier MCU phase announcements ran almost like clockwork every couple of years, however with the secrecy required for the final stages of the "Infinity Saga," news of future films was scarce.
Marvel Studios Phase Four includes a number of interesting films, including sequels like Doctor Strange in the Multiverse of Madness and new potential franchises like Eternals. However, noticeably missing from the announcement was any of the properties acquired from 20th Century Fox, like the Fantastic Four or the X-Men. Their absence is understandable, but fans still can't help speculating about their inevitable debut in the MCU. But when the X-Men finally arrive, which of their iconic villains should appear in the MCU as well?
10 ARCADE
Arcade is easily one of the most added entries on any fan-made casting call and with good reason. The sadistic billionaire assassin uses his funhouse theme to create elaborate deathtraps that he routinely puts a number of Marvel heroes in, beginning with Spider-Man and Captain Britain from Arcade's first appearance in 1978's Marvel Team-Up #65.
Arcade set his sights on the X-Men and their related teams fairly early on in his career, and his deathtrap setpieces - usually ominously dubbed Murderworld - would serve as a fantastic way to introduce the X-Men and their abilities, while also finally bringing the fan-favorite character to the big screen.
9 X-CUTIONER
The X-Men have already had a fairly storied cinematic history and introduced a number of villainous characters over the course of six main films and other spin-offs. However, when it comes to the human antagonists, who are always the most hurtful threat the X-Men have to deal with, has largely been represented by William Stryker and more recently, Bolivar Trask.
Introducing FBI Agent Carl Denti would showcase another human threat to the new X-Men without retreading old villains, while also teasing possible future additions to the franchise. As the X-Cutioner, Denti uses confiscated alien weapons, including a Shi'ar power lance, which could lay some groundwork for the X-Men to finally see some of their space adventures adapted.
8 SAURON
We've already seen a number of iconic comic book locations appear in Fox's X-Men franchise, and it stands to reason that Marvel Studios would likely be looking to explore new areas of the X-mythology. While never before seen on the big screen, the X-Men have always had a unique connection to the Savage Land, a prehistoric jungle paradise hidden in the Antartic.
If the Savage Land is making an appearance in the MCU, Karl Lykos/Sauron needs to be along for the ride as well. Lykos is a mutated energy vampire who feeds on mutants, which transforms him into a humanoid Pteranadon known as Sauron. Sauron's hypnosis powers have always made him a formidable foe for the X-Men, especially in his adopted home turf of the Savage Land.
7 REAVERS
As previously stated, humanity is often mutantkind's greatest enemy, as the world that hates and fears them is ever constant. As the mutants become more powerful and gathered in groups like the X-Men, so too did a select group of humans, who became the cybernetically enhanced mercenaries known as the Reavers.
While the initial group mostly existed to take vengeance on Wolverine, they were eventually reorganized by the cyborg Donald Pierce, who was played by Boyd Holbrook in Logan. The Reavers showcase the extremes some of humanity will go to seek revenge, and would admittedly look pretty awesome on the big screen.
6 CAMERON HODGE
The Reavers weren't the only humans who found themselves cybernetically modified in order to fight the mutant threat of the X-Men, as we saw during the "X-Tinction Agenda" storyline. Cameron Hodge was the leader of an anti-mutant hate group known as the Right, who weaponized their fanatics with robotic suits of armors known as Smileys.
"X-Tinction Agenda" saw Hodge, who had previously been decapitated, replace his entire body with a hulking robot that he would continue to use as the leader of the Right for years. Cameron Hodge not only showcases the worst of humanity in ways the X-franchise hasn't seen, but his evolution into a robotic monster fits perfectly with the established history of the MCU.
5 BASTION
We previously mentioned Bolivar Trask, a human who plays a pivotal role in the ongoing struggle between human and mutants. Trask created the Sentinels, and while we would love to see more comic accurate versions of the Sentinels in the MCU's take on the X-Men, there is another way Marvel Studios could adapt the Sentinel threat.
Bastion first appeared during the "Operation: Zero Tolerance" storyline, which introduced cybernetically altered human sleeper agents Prime Sentinels. They were controlled by Bastion, who himself is a Sentinel/Nimrod hybrid. His futuristic tech coupled with the body-horror themed Prime Sentinels would make for a fantastically visual enemy for the X-Men to face in the MCU.
4 OMEGA RED
We've been discussing a number of big bads that could carry an X-Men film in the MCU based on their fan appeal and threat level. Omega Red is not necessarily on the same level of big bad as some of the other entries on this list, but his fan appeal and visual cinematic potential more than earns him a place on the list.
Omega Red is basically the Russian equivalent to Sabretooth or Wolverine as he is a mutant who had been heavily experimented on. His mutant ability to produce deadly pheromones known as Death Spores was augmented with the Russian government's attempts to recreate Adamantium, resulting in life-draining Carbonadium prehensile coils that extended from Omega Red's wrists.
3 MOJO
Easily one of the oddest villains the X-Men have ever had to face, Mojo is the ruler of the Mojoverse, an alternate reality that lives on entertainment that is usually based on the adventures of the Marvel universe. Mojo's fascination with the X-Men have led to many trips to the Mojoverse, as well as introduced a number of characters like Longshot and Shatterstar to the X-Men.
What's really interesting about the Mojovberse in the large scale of the MCU's multiverse, is that while there can be many alternate realities in the MCU's multiverse, there is only one Multiverse which acts as a hub to all of the various realities. this could be an integral story element that could be used to introduce the X-Men, considering the new phase's focus on the Multiverse.
2 MARAUDERS
Aside from Magneto's various Brotherhood's and Apocalypse's Horsemen, there haven't been too many mutant teams seen in the previous X-films. it would make sense for a superhero team to take on a supervillain team, and the X-Men really only have one team of mutant villains vicious enough to make a memorable debut in the MCU alongside the team.
The Marauders first appeared during the legendary "Mutant Massacre" storyline, which featured the team of killers as they hunted through the sewers of Manhattan, murdering the mutant Morlocks who hid under the city. The Marauders devastated the X-Men during their first comic encounter and would make for an equally fantastic test for the MCU's mutants during their cinematic debut.
1 MISTER SINISTER
Finally, in no surprise to anyone, the X-Men villain fans are most hoping to appear on the big screen is the evil geneticist known as Mister Sinister. Sinister was first mentioned as the master behind the Marauders, who had ordered the mutant killers to cull the Morlocks.
Sinister's obsession with the mutant gene, and Scott Summers and Jean Grey, in particular, could serve as a useful way to properly introduce the mutant gene to the MCU, while also finally bringing one of the X-Men's greatest villains to the big screen.