Iron Monger
Obadiah Stane was the business partner of Tony Stark and a good friend of his father, Howard Stark. After Howard's death, Stane became interim CEO of Stark Industries until Tony officially took over shortly after.
Abomination
Emil Blonsky is a former special-ops commander of the British Royal Marines who was loaned to SOCOM. In his efforts to apprehend Hulk, Blonsky was recruited by United States Army General Thaddeus Ross and injected with a variant of the Super Soldier Serum. After losing to Hulk during a battle, Blonsky had himself transfused with Banner's gamma-irradiated blood, causing him to transform into the Hulk-sized Abomination.
Whiplash
Ivan Antonovich Vanko (Russian: Иван Антонович Ванко) was a Russian physicist and the son of the disgraced scientist Anton Vanko. When Vanko's father died penniless due to the actions of Howard Stark, Vanko swore to seek revenge by targeting Howard's son, Tony Stark. Recreating an Arc Reactor based on his father's design and designing an armor similar to Iron Man's, Vanko attacked Stark in Monaco, under the moniker of Whiplash.
Loki
Loki Laufeyson was the biological son of Laufey, King of the Frost Giants, who was abandoned and left to die shortly after his birth. Found by Odin, Loki was taken to Asgard and raised by him and Frigga as an Asgardian prince, along with Thor, becoming the Asgardian God of Mischief.
Red Skull
Johann Schmidt is the former head of HYDRA, the special weapons division of the Nazi Schutzstaffel and a modern-day incarnation of the ancient society. Having become a confidant of Adolf Hitler during World War II, Schmidt gained ambitions to become the superior man, leading him to use the prototype of Abraham Erskine's Super Soldier Serum on himself, resulting in him becoming disfigured with a red face, gaining the name Red Skull.
Aldrich Killian
Doctor Aldrich Killian was the founder and CEO of Advanced Idea Mechanics. When Tony Stark had refused to join his research, Killian participated in Maya Hansen's development of Extremis, amassing a group of Extremis-enhanced soldiers under his command. To mask his illegal activities as terrorist attacks, he adopted the legend of the Ten Rings and an idealized terrorist persona known as the "Mandarin"
Malekith
Malekith (Shiväisith: Mälekith) was the cruel and malevolent leader of the Dark Elves, a race of beings that thrived in primordial darkness before the Big Bang. Born in a realm of complete darkness, Malekith led his people in a war against the Asgardians, using an ancient weapon known as the Aether in an attempt to revert the universe to a state of complete darkness. Malekith was thought to have been wiped out with the rest of his race in the final battle against the Asgardian King Bor in 2988 B.C. during the Convergence.
Winter Soldier
James Buchanan "Bucky" Barnes is a World War II veteran, former officer of the 107th Infantry Regiment and the best friend of Steve Rogers since childhood. Barnes had enlisted into the Army following the attack on Pearl Harbor and was assigned to the 107th in 1943. His unit was captured by HYDRA, where Barnes was injected with the Super Soldier Serum by Arnim Zola. Barnes was rescued by Rogers, who had become Captain America. Barnes and Rogers then formed the Howling Commandos to battle Red Skull's forces. However, during the attempt to finally capture Zola in the Austrian Alps, Barnes was caught up in the ambush and plummeted hundreds of feet. As no body was recovered, Barnes was presumed deceased and honored as a hero who died in service to his country.Unbeknownst to his team, Barnes' enhanced abilities allowed him to survive the fall, albeit with the loss of his left arm. Once he was found by the Soviet Armed Forces and HYDRA, Barnes was brainwashed and armed with a new cybernetic arm in order to become their operative, known as Winter Soldier.
Ronan the Accuser
Ronan was a radical Kree warlord and a former Accuser of the Kree Empire. A participant in the Kree-Skrull War, Ronan worked with Yon-Rogg and the Starforce after the Ambush in Torfa to wipe out the last of the Skrull refugees. Ronan and the Accusers were then called to drop warheads on Earth to wipe out the remaining Skrull opposition there, but were repelled when Captain Marvel came to Earth's defense. The Accusers retreated, with Ronan promising retribution.
Ultron
Ultron was an artificial intelligence who was originally designed to be part of a peacekeeping program created by both Tony Stark and Bruce Banner, using the decrypted code derived from the Mind Stone encased within Loki's Scepter.
Yellowjacket.
Darren Agonistes Cross was an individual who had the ability to enlarge himself with a suit, making him known as Yellowjacket.
Zemo
Baron Helmut J. Zemo is a Sokovian nobleman, former Colonel of the Sokovian Armed Forces, and commander of EKO Scorpion. Following the Battle of Sokovia, Zemo became a criminal mastermind who had sought revenge against the Avengers and other enhanced individuals, after losing his entire family, and became obsessed with destroying them.
Dormammu
Dormammu is an inter-dimensional entity who rules over the Dark Dimension and the uncle of Clea. Dormammu lent his power to Kaecilius and his Zealots, who desired immortality, in exchange for them merging the Dark Dimension with Earth.
Ego
Ego was a Celestial, a primordial and powerful being, and the biological father of Peter Quill and Mantis. A living planet with a humanoid extension of himself, Ego sought to find meaning in his life and, to achieve this end, planned to remake the entire universe via an omnicidal extinction-level event known as the Expansion, using "seeds" planted on various worlds to terraform them into new extensions of himself, thereby eradicating all other life in the universe but himself.
Vulture
Adrian Toomes is the former owner of Bestman Salvage who lost his livelihood after Damage Control, a joint venture between the federal government and Stark Industries, took over salvaging operations in New York City. Recruiting his co-workers and equipping himself with a flying exo-suit that Tinkerer created using Chitauri technology, Toomes took on the identity of the Vulture and became a black market arms dealer.
Hela
Hela Odinsdottir was the Asgardian Goddess of Death and former Executioner of Asgard. Imprisoned in Hel for millennia by her father Odin, Hela was only released from her prison in the wake of his death and went to restore her power over Asgard while simultaneously engaging in a series of encounters with her younger brothers Thor and Loki.
Erik Killmonger
N'Jadaka, legally known as Erik Stevens, was a former United States Navy SEAL and the son of the Wakandan Prince N'Jobu. When N'Jadaka was a child, his uncle T'Chaka killed his father for trying to murder Zuri for outing him after he had aided Ulysses Klaue in stealing vibranium from Wakanda. This drove Killmonger to dedicate his life to forcibly dethrone his cousin, T'Challa, in order to finally accomplish his father's plan to seize control of the world by using all of Wakanda's vibranium technology to cease the oppression of people of African descent all across the world. In order to achieve this, N'Jadaka joined the Navy Seals and was eventually assigned to a black-ops unit, where his numerous confirmed kills earned him the nickname Erik Killmonger.
Thanos
Thanos was a genocidal warlord from Titan, whose objective was to bring stability to the universe by wiping out half of all life at every level, as he believed its massive population would inevitably use up the universe's entire supply of resources and perish. To complete this goal, Thanos set about hunting down all the Infinity Stones, as the combined force of the Stones would grant sufficient power. Thanos forged alliances with Loki and Ronan the Accuser in order to track down some of the Stones. However, both alliances cost Thanos much of his resources, including the Mind Stone and the loyalty of his daughters, Gamora and Nebula. Fed up with all his subordinates' ongoing failures, Thanos made the decision to seek and procure the Stones himself, and he began by forcing Eitri to create the Infinity Gauntlet for him so that he would have been able to wield the power of the Stones safely.
Ghost
Ava Starr is the daughter of Elihas and Catherine Starr, who gained the ability to render herself intangible and generate extreme amounts of power following a quantum accident which killed her parents. At a young age, S.H.I.E.L.D. began taking advantage of her powers, enlisting her as a stealth operative under the moniker of Ghost prior to HYDRA's uprising.
Mysterio
Quentin Beck was a former employee at Stark Industries who became embittered when Tony Stark stole credit for his holographic technology before firing him. Seeking his retribution, Beck joined forces with other bitter ex-Stark employees to act as a new superhero named Mysterio.
Taskmaster
Antonia Dreykov is the daughter of General Dreykov. Having been gravely injured during an assassination attempt on her father, Antonia had her mind and body controlled by a chip, which imbued her with uncanny photographic reflexes that allow her to mimic the fighting techniques of other individuals, turning her into Taskmaster.
Xu Wenwu
Xu Wenwu (Mandarin: 徐文武) was a legendary and nearly mythical figure who rose to power after discovering a set of mythical rings, and founded the army known as the Ten Rings. Xu established himself as a powerful warlord who conquered kingdoms over the millennia, the rings' power gifting him immortality.
Green Goblin
Doctor Norman Virgil Osborn is a scientist and CEO of Oscorp, who experimented on himself with an incomplete enhancement serum, causing Osborn to develop an alter known as Green Goblin.
Wanda(Scarlet Witch)
Wanda Maximoff was a native of Sokovia who grew up with her fraternal twin brother, Pietro. Born with the latent mythical ability to harness Chaos Magic, she developed a hatred for Tony Stark and rallied anti-American protests after the Novi Grad Bombings killed her parents.
Gorr the God Butcher
Gorr was a vengeful galactic killer who sought the extinction of all gods, coming to be known throughout the galaxy as the God Butcher. Once a devout and peaceful man, Gorr lost his faith after the death of his daughter. Enraged at how the gods belittled his suffering, Gorr happened upon the All-Black the Necrosword.
Namor
King Ch'ah Toh Almehen is a Talokanil mutant who rules the underwater kingdom of Talokan. As he aged slowly and gained the respect of the Talokanil, they started to worship him as K'uk'ulkan.[4] Following his mother's death, he visited the surface world and witnessed the atrocities of Spanish colonization, causing him to take violent action, earning him the name Namor from his enemies.
M.O.D.O.K.
Doctor Darren Agonistes Cross was the protégé of Hank Pym who usurped his mentor as CEO of Pym Technologies and rebranded it as Cross Technologies. Cross became obsessed with the Pym Particles and using Pym's technologies to achieve success, but the constant exposure to the particles negatively affected his mind. Cross had developed the Yellowjacket Suit and intended to sell it to HYDRA and the Ten Rings but Pym and Hope van Dyne joined forces with Ant-Man who destroyed his entire research.
Kang the Conqueror
Victor Timely was a scientist from the 31st Century who discovered the Multiverse's existence and joined the Council of Kangs in ruling over the foreseeable realities. Deeming the council's actions to be destroying the Multiverse, Timely sparked the Multiversal War, seeking to conquer as many worlds as possible as Kang the Conqueror.
High Evolutionary
High Evolutionary is a geneticist who sought to create a perfect species out of what he viewed as lower life forms, and build his own utopia. Founding his own research company OrgoCorp as a front for his genetic engineering experiments, he was responsible for the creation of numerous lifeforms across the galaxy.
Leader
Doctor Samuel Sterns is a cellular biologist and Grayburn College professor who was finding a cure for Bruce Banner. Sterns managed to engineer a temporary antidote for Banner's condition but was also forced to repeat this process with Emil Blonsky, transforming him into Abomination. When he was affected by Banner's blood on his head's open wound, his mind suffered a rapid mutation, greatly increasing his mental abilities.