Every Major Marvel Villain That Joined the Avengers

Many of the greatest heroes in the Marvel Universe did not start as such. Fueled by a desire to atone for past mistakes and, in some cases, a villainous background, these powerful figures sought redemption through acts of heroism.

This certainly holds true for the Avengers. Several of the team’s most popular heroes started as deadly super villains before a heroic change of heart set them on a different path. In a surprising number of cases, the Avengers provided a rather permanent path to redemption, with very few reformed super villains reverting to their wicked ways.

In light of Ultron joining the ranks of the West Coast Avengers in Gerry Dugan and Danny Kim’s WEST COAST AVENGERS (2024) #1, here are all the major instances of super villains joining the Avengers. Redemption is on the table, but which of these villains will take it? Find out below!

CAP’S KOOKY QUARTET

Fans now know Hawkeye, the Scarlet Witch, and Quicksilver as cornerstones of the Avengers, but that was not always the case. Each of these characters made their respective debuts as villains.

Though reluctant, Clint Barton initially started his stint as Hawkeye as an accomplice to Black Widow by helping the Russian spy sabotage Iron Man. Clint’s association with Black Widow branded him a villain in the United States.

Meanwhile, Quicksilver and Scarlet Witch antagonized the X-Men as part of Magneto’s Brotherhood of Mutants. Growing tired of Magneto’s antics, the brother-sister duo later decided to step away from the Brotherhood.

When the founding Avengers took an indefinite leave of absence, Iron Man saw the inherent heroic qualities of these villains and recruited them onto the Avengers in AVENGERS (1963) #16. Under the leadership of Steve Rogers, these reformed villains became known as Cap’s Kooky Quartet.

However, being a part of Earth’s Mightiest Heroes did not ease friction between these new recruits. Hawkeye frequently chafed under Captain America’s straightforward leadership, while Quicksilver resented Hawkeye’s clear romantic interest in his sister.

The team overcame these interpersonal issues and formed an effective unit, squaring off against villains like Kang the Conqueror and Doctor Doom.
 

BLACK WIDOW’S REDEMPTION

Although she is one of the most recognizable Avengers today, Black Widow first crossed paths with Earth’s Mightiest heroes as an assassin trained in the Soviet Union’s Red Room. Introduced in TALES OF SUSPENSE (1959) #52, the highly trained Soviet super-spy targeted Tony Stark at the behest of her government.

After her former accomplice Hawkeye joined the Avengers, Natasha Romanova sought to defect from the Soviet Union. Sensing Natasha’s wavering loyalty, her masters hunted her down and brainwashed the Black Widow into submission.

Once Natasha’s conditioning broke, Nick Fury recruited her to spy on her former masters on behalf of S.H.I.E.L.D. Black Widow officially joined the Avengers in AVENGERS (1963) #111 and became one of the team’s longest running allies. 

SANDMAN, RESERVE AVENGER

While primarily known as a major Spider-Man villain, Sandman has turned towards heroism at various junctures, in an attempt to atone for his criminal past. 

After an encounter with the Thing in MARVEL TWO-IN-ONE (1974) #86, Sandman started to question his morally dubious actions. This culminated with Sandman sporadically teaming up with Spider-Man against other villains, starting with MARVEL TEAM-UP (1972) #138 when the former foes took on the Enforcers together.

As Sandman continued down the road to redemption, he received a presidential pardon and officially became a reserve member of the Avengers in AVENGERS (1963) #329.

Unfortunately, Sandman’s heroic turn proved to be temporary, with Flint Marko returning to villainy under the influence of the Wizard in AMAZING SPIDER-MAN (1999) #4. While Sandman does the right thing at times, he maintains his status as Spider-Man villain to this day.
 

INTRODUCING THE DARK AVENGERS

After Norman Osborn killed the Skrull Queen in SECRET INVASION (2008), the American government entrusted him with H.A.M.M.E.R., the intelligence agency that replaced S.H.I.E.L.D. after they failed to prevent the extraterrestrial infiltration.

With the super hero community declared enemies of the state, Osborn introduced his own version of the Avengers in DARK AVENGERS (2009) #1. Led by Osborn as Iron Patriot, this Avengers lineup featured a mix of Osborn’s old teammates on the Thunderbolts and villains pretending to be established heroes like Spider-Man and Hawkeye.

Osborn and the Dark Avengers learned the hard way that being a hero is not as easy as it seems. In between battles, the Dark Avengers struggled to hide their true intentions from the public, leading to greater scrutiny into their activities.

The true Avengers defeated their dark counterparts during SIEGE (2009) following their attack on Asgard. The Dark Avengers disbanded, with many of its members arrested.

RED HULK JOINS THE AVENGERS
 

The Intelligencia, consisting of M.O.D.O.K. and the Leader, recruited General Thunderbolt Ross to become their ultimate weapon: Red Hulk. While he eventually betrayed this group, Red Hulk went mad with power. Ross took over the White House, with only the Incredible Hulk being able to stop him.

In the aftermath of SIEGE (2009), various new Avengers teams formed to defend the Marvel Universe. During this period, both Bruce Banner and Captain America took a particular interest in the redemption of General Thunderbolt Ross.

After Banner defeated Ross and stopped his White House takeover in HULK (2008) #24, Steve Rogers approached the dishonored military general in his search for some serious muscle on his reformed Avengers roster. 

The Red Hulk played a pivotal role on the Avengers, helping them recover the Infinity Stones in AVENGERS (2010) #12 and defending Earth during an attack by the Asgardian God of Fear in FEAR ITSELF (2010).

General Ross isn’t the only Red Hulk in the Marvel Universe, nor is he the only Red Hulk to serve as a member of an Avengers team. General Robert Maverick received an experimental device that allowed him to turn into the Red Hulk for approximately one hour at a time and used his immense powers as a member of the U.S.Avengers in U.S.AVENGERS (2017) #1. 

Maverick continued to serve on the U.S.Avengers through SECRET EMPIRE (2017) before eventually being depowered in AVENGERS (2016) #684 after a grueling battle against the Hulk.

LOKI AND THE YOUNG AVENGERS

When an unstable Scarlet Witch temporarily disbanded the main Avengers team in AVENGERS (1998) #503, the Young Avengers formed in its place. 

While the original Young Avengers roster featured Iron Lad, a teenage variant of Kang the Conqueror trying to circumvent his villainous fate, he was far from the least noble figure to join the team. That title was reserved for Loki, the God of Mischief trapped in the body of his younger self. 

The Young Avengers cautiously welcomed Kid Loki into their ranks in YOUNG AVENGERS (2013) #3 after he rescued Wiccan and Hulkling. Though Loki initially joined the team to try steal Wiccan’s powers for himself, he came to genuinely care for his teammates.

Overrun with guilt, Loki left the team in YOUNG AVENGERS (2013) #15, feeling himself unworthy of their forgiveness as he continued to search for his own place in the world.

VENOM AND THE WAR AVENGERS

When the Dark Elf Malekith the Accursed launched a full-scale invasion of Earth in WAR OF THE REALMS (2019), both heroes and villains needed to pull their weight to stop him. 

At the time, Eddie Brock and the Venom symbiote were temporarily separated. However, Venom independently joined the resistance force known as the War Avengers, fighting Malekith’s armies alongside Captain Marvel, Deadpool, and Black Widow.

Venom’s time on the War Avengers quickly proved disastrous, with Malekith using his magic and the Ebony Blade to subdue the symbiote. Taking Venom back with him to his base of operations, Malekith tortured the symbiote into becoming his new weapon.

Though Venom eventually bonded with Eddie once more, the symbiote’s first time as an Avenger was not particularly successful.

ULTRON AND THE WEST COAST AVENGERS

Created by Hank Pym, Ultron debuted in AVENGERS (1963) #57 and rebelled against his creator, vowing to eradicate humanity. Since then, the villainous android has threatened the entire Marvel Universe on numerous occasions, turning him into one the Avengers’ most dangerous foes.

When Tony Stark and James Rhodes decided to reassemble the West Coast Avengers in WEST COAST AVENGERS (2024) #1, they made a very unusual decision: they invited Ultron to join their ranks.

Will Ultron redeem himself, or will he betray the team in a calculated scheme? Tune in to WEST COAST AVENGERS #2 to find out!

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