A recently leaked toy for Avengers 4 came with a description that suggested the Avengers could be facing a threat even bigger than Thanos. It's hard to imagine anyone in the MCU more dangerous than the Mad Titan after he destroyed half the universe, but if this rumor holds true, Earth's Mightiest Heroes may have just faced just the tip of the iceberg. With discussion of who or what this "bigger threat" could be, one doesn't have to look far. Marvel Comics have featured several cosmic villains who have threatened the Avengers, Fantastic Four, and X-Men on a grand scale. All Marvel Studios needs to do is look through one of these major arcs and adapt the villain to the big screen. Entire storylines have been dedicated to the tyranny of new villains that threaten the universe as a whole -- it wouldn't be too difficult for Marvel to use one of them in a movie.
On top of that, the upcoming deal with FOX and Disney could open the door for the villains Marvel could choose in the future. It's possible that an X-Men or Fantastic Four villain could be on the horizon (it being for A4 is most likely wishful thinking), but we don't think characters like Doctor Doom or Onslaught are going to make an MCU appearance anytime soon. Either way, it seems that the Avengers and Guardians of the Galaxy have yet to face their greatest threat. With a "bigger threat" approaching the MCU, we discuss 20 overpowered villains that could fit the bill.
20 ANNIHILUS
When the rumors first came out that a new villain could appear in Avengers 4, some were quick to speculate that it was a hint that Annihilus could be the new bad guy. After the additional rumor that Avengers 4 would be titled Avengers: Annihilation, it wasn't long before fans put two and two together.
Annihilus is a villain that predominantly fights the Fantastic Four, but Marvel and FOX have made deals in the past to acquire use of certain characters. Furthermore, Annihilus was also responsible for a huge storyline in the comics titled "Annihilation." Having that large-scale impact in the comics could easily translate to the MCU.
19 CELESTIALS
The Celestials have already been confirmed to exist in the MCU, with Ego the Living Planet being one of them. While the Celestials seem to have been long gone, it's likely to believe that there are some still around. With Thanos disrupting the balance of the entire universe, it's possible that this could prompt a malevolent Celestial to either capitalize or try to correct the damage.
Either way, an incoming Celestial would be a threat that prompts the Avengers to action. Being essentially the gods of the MCU, they would easily have greater power than the Mad Titan. It could also serve as an entry point into wackier stories in the MCU to come.
18 BEYONDER
"Secret Wars" was one of the biggest storylines in comic history and it all happened because of one entity: the Beyonder. While there haven't been any hints of the Beyonder in the MCU, it's important to mention that he did live in a different dimension in the comics. As a way of figuring out how to stop Thanos, the Avengers could inadvertently open a portal to this new world and unleash the Beyonder.
To fit in the MCU, it's likely that Marvel would have to change his design, as seeing an '80s-inspired all-powerful being flying through the universe would be a bit difficult for modern audiences to digest.
17 GALACTUS
Perhaps one of the most iconic cosmic villains in Marvel history, Galactus has made his mark on the Marvel Universe several times. Despite already appearing in live-action in Fantastic Four: Rise of the Silver Surfer, it's possible that Marvel worked to try and include him in the MCU.
Not only would Galactus' inclusion be a serious crowd-pleasing moment, but it could also tie into the lore of the MCU. Galactus is a Celestial, and the knowledge that the universe was much more vulnerable could prompt him to go on an eating spree, devouring every planet in his path.
16 KANG THE CONQUEROR
Kang the Conqueror has intelligence and time travel on his side, which are all he needs to get the best of the Avengers. It would be all too easy to incorporate him. He could be from a distant future where Thanos' snap has destroyed the universe rather than saved it.
Traveling back in time, he could seek to defeat the Mad Titan and get a further thirst for power. Kang the Conqueror was also the antagonist of LEGO Marvel Superheroes 2, a game that was devoid of characters that FOX had the film rights to. This could suggest that Marvel Studios has been planning to use Kang in an upcoming film.
15 MAGUS
Adam Warlock, while not free from his cocoon yet, already exists in the MCU. Created by the Sovereign, he was designed to destroy the Guardians of the Galaxy. One way to build up his presence would be to have Magus appear in Avengers 4. A version of Warlock from the future, Magus was evil and sought to destroy the universe.
While there would be something missing with the Warlock/Magus dynamic gone, having the Guardians of the Galaxy fight a future iteration of a character they're bound to meet could prove interesting for the franchise. It would also better tie Warlock's teased presence in Guardians of the Galaxy Vol. 3 (presuming Disney is going through with it).
14 DORMAMMU
Doctor Strange introduced two villains in the form of Kaecilius and Dormammu. The man that Strange fought, Kaecilius, was just a man working for Dormammu. When the film was over, Strange didn't defeat Dormammu, he outsmarted him instead. This means that Dormammu is still in the Dark Dimension and has his sights set on Earth.
With the knowledge that Strange has been destroyed by the Infinity Gauntlet, Dormammu could see his opportunity to take over the Earth. Without the help of Strange, the Avengers would have no clue how to defeat this new foe, which could prove interesting for the film.
13 CHAOS KING
A threat that has attacked the entire multiverse, the Chaos King is as powerful and scary as they come. Having a desire to conquer all of the god pantheons as shown in Ares: God of War, Chaos King seems to have no limits. He can destroy entire worlds, battle other gods, and always come out on top.
He's not that well-known of a character, though that hasn't stopped Marvel from including a character in a film before. With the knowledge that Asgard and the rest of the universe are in shambles, Chaos King could begin making his move to re-shape the MCU in his image.
12 AKHENATEN
Cursed for his treatment of the Egyptian gods, Akhenaten was changed for the rest of his life. He was later granted access to an object that would essentially turn him into a god. In his universe, Akhenaten was sent to Earth, where he laid waste to just about every superhero in existence.
Probably the least likely candidate on this list, Akhenaten could be the loose result of Thanos' finger snap. He could also be an entity that is either intentionally or accidentally summoned from an alternate dimension by the Avengers. He could even be a Celestial, leading Marvel to alter him specifically for Avengers 4.
11 THANE
Thanos did not live his life with no heirs to his throne of madness. In the "Infinity" arc, it was revealed that he had a son named Thane, whose powers would only be fully activated after being exposed to the Terrigen Mist. While the story of Thane is heavily involved with the Inhumans, it would be easy for Marvel to change things around for the MCU.
Thane could be created as a result of Thanos living in peace. However, Thane could also be much stronger than his father, prompting the Avengers to grudgingly team up with the Mad Titan they once fought.
10 KORVAC
Michael Korvac was one of the smartest men in the Multiverse. Born in a different reality before coming to the primary Marvel Universe, he was blessed with knowledge. Eventually, he gained access to great cosmic knowledge that allowed him to become his own god with a perfect physical form.
This came with a set of powers that made him a deadly cosmic being. While not having many ties in the MCU, Korvac is a character that could easily be written in as the story needs. If Marvel wanted to make things simpler, he could just be someone native to the main universe that gained access to immense power.
9 THE FALLEN ONE
Galactus is known for turning various creatures into his servants, like what he did to the Silver Surfer. The first of his servants was the Fallen One. Blessed with dark energy rather than the Power Cosmic, the Fallen One proved to be a malevolent being and tried to destroy his master several times.
As a result, the Fallen One was cast away, destined to be imprisoned or fighting other cosmic entities like Thanos. The Fallen One could be a new threat for the Avengers to face in Avengers 4. After defeating him, it could be revealed that he was simply a herald of Galactus: an even greater threat to show up in Phase Four.
8 MOLECULE MAN
Owen Reece was smart but careless. During one of his experiments, he wasn't watching his surroundings closely enough and was subject to a serious accident. As is the case with comic book characters, Reece was given awesome powers instead of serious injuries. He found himself with the power to alter matter at a molecular level.
This gave him the ability to dismantle anything that stood in his way, even the Avengers. This sort of power could be an interesting threat in Avengers 4, though it would probably be more difficult to weave into the story set up in Avengers: Infinity War.
7 TYRANT
Tyrant was another one of Galactus' servants, but he was known for his immense power and thirst for conquest. After Tyrant was created, he hatched a plan to overthrow his master and take over the universe. The two fought and Galactus barely won. Tyrant was so powerful that even Thanos knew the legends of his strength.
Tyrant could be woven into the MCU by restructuring him as a Celestial. Sensing the imbalance caused by the Infinity Gauntlet, Tyrant could see his opportunity for conquest and try to take over. It would serve as an interesting way of making Thanos regret his actions.
6 THE SERPENT
Odin has been known to keep a lot of secrets from his family. Not only was Loki revealed to be a Frost Giant, but Hela was also a secret first-born that didn't return until after his death. In the comics, Odin also had a brother known as the Serpent, the God of Fear.
After the fall of Asgard in Thor: Ragnarok and Avengers: Infinity War, it might be time for Serpent to make his move. Knowing that his nephew still lives, Serpent could try to take on the Asgardian king as a way of ending his brother's line once and for all. That would be an awfully Thor-centric move by Marvel, but they seem to be giving him more screen time anyway.
5 ARON THE WATCHER
The Watchers are a race of beings whose goal is to simply watch over the universe. They are not to interfere or get involved. However, Aron the Watcher wasn't fond of this rule and found it exciting to meddle with the humans of Earth and was fought off by other Watchers as a result. The Watchers were already confirmed in the MCU during Guardians of the Galaxy Vol. 2.
While it was a neat easter egg, it's possible that it could lead to something a bit more interesting in Avengers 4. With the universe falling apart, Aron could decide to get involved and try to reshape the world in his own way, prompting the Avengers to fight him as well.
4 THE SKRULLS
The Skrulls are making their live-action debut in Captain Marvel. Above all things, they were mostly known for taking the appearance and powers of Marvel heroes and masquerading as them only to try to take over Earth during "Secret Invasion". Marvel could play around with this in Avengers 4, having the Skrulls begin making their move after the universe and its heroes are in disarray.
They could slowly reveal themselves, organizing a plan to conquer the universe with their remaining members, which could be the reason that Captain Marvel more readily gets involved. It's a bit of a stretch, but we doubt Marvel is introducing the Skrulls to only use them in one movie.
3 THE REAL MANDARIN
Fans of the Mandarin were extremely disappointed when Iron Man 3 revealed that it was just a man acting the part. The Marvel one-shot "All Hail the King", countered that by stating the Ten Rings was a powerful organization and was led by a character known as the Mandarin. Avengers 4 might be the time to capitalize on that subtle tease.
This way, Marvel could embrace the more power-heavy side of the Mandarin and give him all the abilities he had in the comics. While it would be a bit random to introduce such a character, he at least has a background in the MCU.
2 THE GRANDMASTER
In Thor: Ragnarok, it was unclear just how much power the Grandmaster had. Despite being the head of an entire planet and carelessly controlling all sorts of champions, his power level was never fully shown. He was still alive at the end of the film, but the Collector met his end in Avengers: Infinity War.
Considering the two were brothers in the comics, it's possible that the same could be true in the MCU. After getting wind of his brother, the Grandmaster could decide to make his move to control the universe, going straight for Thanos and Thor along the way.
1 KREE EMPIRE
The Kree have proven to be one of the most resilient organizations in the Marvel Universe. In the MCU, they first appeared in Guardians of the Galaxy and are set to appear again in Captain Marvel. Such a massive civilization could easily have more impact in the MCU going forward. While they don't have Ronan the Accuser on their side, they should have plenty of firepower on their own.
After half of their people perished, they could easily decide to rampage across the universe, somehow blaming the Avengers in the process. It would then be up to Earth's Mightiest Heroes to solve that problem as well.