Loki – Thor's archenemy and adoptive brother. The son of Laufey, ruler of the Frost Giants of Jotunheim, one of the "Nine Worlds" of the Asgardian cosmology. He is a master of spellcasting and trickery. Lorelei – The sister of Amora the Enchantress, who possesses some skills in Asgardian magic and seduction.
As a heroine, many of Carol's deadliest foes are of Kree origin, including Ronan the Accuser, the Supreme Intelligence, Yon-Rogg, Doctor Minerva, and Doctor Eve. Deathbird of the Shi'ar has been a constant nemesis for Carol, but Mystique, M.O.D.O.K., and Moonstone also have a long history with her.
Red Skull: Johann Schmidt AKA The Red Skull is generally considered to be Captain America's archenemy. He is a man with intense hatred for others, which lead to him being trained as Hitler's apprentice to be the, "Perfect Nazi".
The Red Skull is a character, a supervillain that appears in comic books published by Marvel Comics. He is the archenemy of the superhero Captain America, and is portrayed as a Nazi agent. Created by Joe Simon, Jack Kirby and France Herron, the character first appeared in Captain America Comics #1 in March 1941.
Red Guardian: Soviet equivalent to Captain America and a Cold War rival. Red Skull: Captain America's archenemy, a Nazi super-soldier and Hitler's successor.
The Leader (Samuel Sterns) is a supervillain appearing in American comic books published by Marvel Comics. The Leader first appeared in Tales to Astonish #62 (December 1964), created by writer Stan Lee and artist Steve Ditko as the archenemy of the Hulk.
The Norman version of the Green Goblin is usually regarded as Spider-Man's archenemy. The second Goblin, Harry Osborn, is Norman's son and Peter Parker's best friend. He has the same powers as his father.
With the gauntlet, Thanos is without a doubt the greatest threat to the universe, making Captain Marvel simply no match for the Mad Titan. That being said, without the Gauntlet, Thanos isn't nearly as powerful in the MCU.
Odin's *enemies* are, of course, mainly the Giants. Especially Fenrir, as Fenrir is prophesied to devour Odin at Ragnarök. Odin is also no longer a huge fan of Loki's one can assume, as Loki tricked the blind god Hod/Hodr into killing Baldr, Odin's son. But, I'm a human being and can't really speak for Odin as a god.
Killmonger first appears in the live-action film Black Panther. Seeking revenge for his father's death and angered by Wakanda's refusal to use its wealth to assist others, he challenges his cousin T'Challa for his birthright to the throne and seemingly kills him.
Tony Stark's best friend, James Rhodes, is one of the few to wear the Iron Man armor, other than Tony Stark himself. Although he initially took on the role when Stark was dealing with his demons, Rhodes has reprised the role over the years.
Darren Agonistes Cross is a supervillain appearing in American comic books published by Marvel Comics. He is the archenemy of Scott Lang (the second superhero to be called Ant-Man) and the cousin of Crossfire.
His most notable enemy, however, is Loki. With his strong sense of morality, Clint suffers at the thought of having worked against S.H.I.E.L.D. and his fellow agents, mourning the losses at his hand. He blames Loki for this violation, and the Asgardian prince has earned Barton's eternal enmity.
While many people believed that Hulk was afraid of Thanos after his beat down, the directors confirmed in an interview that Hulk was not afraid of Thanos, but rather was sick of being a punching bag for Earth, and thus did not want to come out. The Hulk has no cause to fear anyone, except the Void.
Remember that Gray Hulk might be the weakest version of the Hulk of all-time but there was one other time that Hulk went gray after that original appearance. This was when he turned into Mr. Fixit.
Despite being an unstoppable force, powerful beings like Namor, Wolverine, Iron Man, and Deadpool have managed to outsmart and defeat the Hulk. From fellow superheroes to average soldiers, various characters, including Hawkeye and even Batman, have successfully taken down the Hulk.
