The Marvel Cinematic Universe is slowly, but strongly moving forward to expand it. Whether it’s a movie, a series on Disney+, or even appearing as supporting roles, Marvel just is giving a lot of fan-favorite characters time to shine.
There is no shortage of villains that the Marvel heroes can fight. Villains like Thanos, Hela, Ultron, and Erik Killmonger have set the bar extremely high by being strong characters with strong connections to their hero rivals. It lowered the chances for some villains to appear in the MCU because they might not have the pizzazz that Marvel is looking for or their hero rivals are done.
10 Basil Sandhurst AKA The Controller
A man that worked as a research scientist until he refused ethical restraints. Basil’s older brother Vincent accidentally triggered a lab explosion while trying to calm him. Vincent felt horrible for what he did and created the suit that Basil now uses. He is powered by the cerebral energies around him by using his slave discs.
He was stopped by Iron Man and S.H.I.E.L.D agent Jasper Sewell. Most, if not all, of his appearances, have portrayed him as an enemy of Iron Man. Since Iron Man is now dead in the MCU, the Controller probably won’t ever appear on the big screen. It also doesn’t help that he appears very little in the comics.
9 Morlun
This vampire has appeared as a villain to all of the Spider-Man heroes. Like most vampires, he has to drink blood to maintain his strength and longevity. He’s able to keep up with Spider-Man and has fought him and other versions throughout most of his appearances.
Unfortunately, Morlun hasn’t quite reached the iconic status as other Spider-Man villains like Green Goblin, Doctor Octopus, and Venom. Their stories and overall impact in Spider-Man’s story are just a bit better.
8 Mr. Sinister
A villain that is obsessed with turning humanity into perfect superhumans. He was transformed by Apocalypse into a mutant, gaining superpowers and became ageless. He does have a slight obsession with the relationship of Cyclops and Jean Grey, believing they could reproduce the perfect superhumans that he wants. He even created Madelyne Pryor out of Jean's cell sample and purposely placed her in Cyclops' life after Jean's death. Thanks to his manipulations, Madelyne and Scott have a son together that would grow up to be Cable.
Mr. Sinister would make a great villain for the X-Men to fight. Unfortunately, the X-Men's future in the MCU movies is still up in the air and many are wondering when they'll be introduced. This leaves all possibilities of Mr. Sinister appearing uncertain.
7 U-Foes
A team that was created to be the new Fantastic Four, but ended up taking a different path. They were exposed to stronger cosmic rays that most likely would’ve killed them if Bruce Banner hadn’t stepped in. The four of them believed they could’ve gotten stronger if they had been exposed more and blame Banner for cutting them off.
They are usually enemies of the Hulk, but they’ve only appeared a couple of times. Since there doesn’t seem to be plans for Bruce Banner to have a movie, the U-Foes probably won’t be appearing anytime soon.
6 Nitro
This is the villain who played a part in the death of Mar-Vell, the original Captain Marvel. Nitro was the one responsible for releasing a nerve gas that caused Mar-Vell’s cancer. Since then, he’s appeared alongside other villains and fought multiple heroes. He may have helped take down Captain Marvel, but he hasn’t played any major roles in the comics. It’s very unlikely he’ll appear in the MCU.
5 Proteus
A mutant that was born to a genetic researcher mother and a politician father. He was raised in isolation thanks to his mother. Proteus’ mutant abilities became unstable and craved energy, forcing his mother to lock him in a cell. He was able to escape to his cell thanks to a fight between Magneto and the X-Men, and taking over a body in the process. Proteus saw that his new body wouldn’t be able to handle his powers so he sought to possess a stronger one and targeted Phoenix/Jean Grey.
Since then, he’s tried to take over other bodies, including Polaris. With his immense power, Proteus could be a strong foe for any hero to fight. Now that the X-Men are part of the MCU, no one knows what the future plans are for them. Proteus is going up against big-time villains like Magneto, Phoenix, and the Sentinels. All of them have stronger storylines than him, greatly slimming any possibility of him appearing.
4 Cassandra Nova
Think of her as Charles Xavier’s evil twin. Cassandra Nova’s existence started in the womb of Charles Xaver’s mother. Cassandra is a Mummudurai, a psychic wraith-like being. She didn’t have a body and copied Xavier’s DNA to create her own body. Once she grew hands and feet, Cassandra tried to strangle him with his own umbilical cord, but Charles hit her with a psychic blast that caused their mother to miscarry her. She managed to survive by clinging to a sewer for decades as a chaotic cell matter and managed to create her own body.
Cassandra is one of the most powerful villains the X-Men has ever faced and even took possession of Xavier’s body. She could be a strong villain to face, but the possibility of her appearing in the MCU is low. The X-Men just became part of the MCU and Marvel doesn’t seem to be in a hurry to introduce them just yet.
3 The Maestro
A version of the Hulk from an alternate and post-apocalyptic future. The Maestro is one of the strongest versions of the Hulk. He can do everything the Hulk can do, but he is a lot stronger due to absorbing a century’s worth of radiation and it’s possible his insanity adds to this. Since She-Hulk will probably be picking up the Hulk mantle in the She-Hulk series, bringing in Maestro would seem a little pointless.
2 Blackheart
A demon that was created by supervillain Mephisto. He has tried to corrupt heroes like Spider-Man and Daredevil, usually ending in failure. Believing that evil just won’t win against good, Mephisto banished him. Blackheart tried to recruit heroes for his war against Mephisto, but was turned down. He eventually took over Mephisto’s part of Hell.
When compared to his father, Blackheart is quite weak and not a strong villain. He only got to rule because Mephisto let him destroy him after he fulfilled a prophecy. Blackheart just isn’t a big threat when he’s up against big-time villains like his father or Zadkiel.
1 Todd Arliss AKA Tiger Shark
A villain that is usually portrayed opposing Namor (Marvel’s version of Aquaman). Todd was an Olympic swimmer who was selfish and seeking fame. After attempting to save a drowning man, Todd damaged his spinal cord. Desperate to swim again, Todd agreed to let Doctor Dorcas experiment on him. He was infused with Namor’s DNA and a tiger shark’s DNA. This experiment worked, but it left Todd with a predatory and savage nature and changed him physically, resembling a humanoid shark.
There is a very small chance that Tiger Shark could appear, especially if the rumors are true that Namor will appear in Black Panther: Wakanda Forever. However, Namor is usually portrayed as an anti-hero or teaming up with the Defenders, Fantastic Four, or X-Men. Tiger Shark is a good villain, but he just doesn’t seem like the biggest threat in the world.