The Avengers have dealt with their fair share of disloyalty over the years, which is to be expected considering the huge amount of characters that have made their way on to Earth's Mightiest Heroes. Even recently the team was betrayed by Gorilla-Man in the pages of Jason Aaron and Ed McGuiness' Avengers, though his disloyalty pales in comparison to other Avengers traitors.
Marvel's premier superhero team has dealt with betrayals that have attacked them personally as heroes and individuals, with some wounds leading to larger betrayals in vicious cycles that have left the team disassembled and disillusioned. Today we are going to look at a few of the vilest betrayals ever suffered by the Avengers by some of Earth's Mightiest Scumbags.
10 IRON MAN
It's hard to picture Iron Man as anything but a hero these days. Sure, arrogant and headstrong were always great descriptors of Tony Stark, but vile and evil? Not Iron Man, who helped found the Avengers. However, as revealed in Bob Harras and Terry Kavanaugh's "The Crossing" storyline, Tony was a pretty big scumbag.
"The Crossing" revealed that Tony Stark had secretly been working with Kang the Conqueror for years, following Tony's murder of Yellowjacket II and Luna Maximoff's nanny Marilla. The betrayal extended back to the beginnings of the Avengers team but was heavily retconned by both Heroes Reborn and Avengers Forever to make Tony less of a piece of crap.
9 ULTIMATE BLACK WIDOW
Mark Millar and Bryan Hitch's The Ultimates featured a new modernized take on the Avengers set in the Ultimate Universe. The new government-sponsored team of heroes and special agents served as partial inspiration for 2012's The Avengers, though thankfully the films chose not to adapt a specific moment of villainy from one of the Ultimates.
During the events of The Ultimates 2, it is revealed that ultimate Black Widow has allied herself with the Liberators against the United States, framed Captain America and Thor, and kidnapped and tortured her fiancé, Tony Stark. Black Widow's betrayal also ultimately led to the complete massacre of her closest ally Hawkeye's family.
8 SENTRY
The Sentry was first introduced in the pages of Paul Jenkins and Jae Lee's The Sentry mini-series before joining Brian Michael Bendis' New Avengers, where he remained for the majority of Bendis' run with the teams. While Sentry wasn't introduced until 2000, he was retroactively included in Marvel history, though his existence was erased from the memories of everyone on Earth.
His time with the Avengers was troubled, as was his time as the Sentry, thanks to the unstable nature of his powers and mental state. This was heavily manipulated by Norman Osborn when he took control of the Avengers, and Sentry eventually broke and allowed his Void persona to take control, where he turned on the Avengers, ripped Ares in half, destroyed Asgard, and killed Loki.
7 HANK PYM
Doctor Hank Pym was the founding Avenger known as Ant-Man, who became Giant-Man, Goliath, Yellowjacket, etc. Pym's use of codenames and identities was somewhat indicative of his mental state over the years, so it's not that surprising that he would end up turning on the Avengers, even if his intentions were noble.
Hoping to bolster his position with the team, Pym created the artificial intelligence known as Ultron to attack the Avengers so Pym could save the day. Eventually, Ultron rebelled, evolved, and became one of the Avengers most deadly villains. However, in Avengers: Rage of Ultron, Pym's consequences of his first betrayal are realized as he was permanently bonded to Ultron, losing his humanity in the process.
6 DOCTOR DRUID
While most would consider Doctor Druid to be an obscure member of the Avengers, he spent enough time with the team to make his eventual betrayal memorable. Druid was initially conceived as Doctor Droom by Stan Lee in the early days of Marvel but was later re-introduced as a student trained by the Ancient One to replace Doctor Strange if needed.
Unfortunately, following manipulations by the woman known as Ravonna/Terminatrix, the telepathic hypnotist/magician used his abilities to mentally take control of the Avengers. Dr. Druid forced She-Hulk to fight her fellow Avengers, which ultimately led to her quitting the team, and after Druid was defeated and lost in the timestream, the Avengers disbanded.
5 MOONDRAGON
Moondragon is not the best known Avenger, but she does have a very interesting origin. Heather Douglas and was the daughter of Arthur Douglas, whose soul would go on to become Drax the Destroyer. Heather would be taken to Titan, where she would train to become an expert combatant with highly developed telepathic and empathic abilities known as Moondragon.
Moondragon worked with the Avengers against cosmic threats like Thanos and Korvac, before finding a war-torn planet that she used her abilities to force into peace. When the Avengers found out they attempted to intervene, though Moondragon mentally took control of Thor, forced him to love her, and used him to attack the Avengers before she was ultimately defeated, and later, reformed.
4 QUICKSILVER
Pietro Maximoff started his costumed career as Quicksilver on the wrong side of the law, working with his sister Wanda on Magneto's Brotherhood of Evil Mutants. Eventually deciding to reform, Pietro and Wanda would join the first new lineup of Avengers alongside another former criminal Hawkeye, under the leadership of Captain America.
Quicksilver would join with the team occasionally over the years, splitting his time between the Avengers, X-Factor, and the Inhumans. Quicksilver has managed to betray each of those alliances in some way over the years. With the Avengers he conspired with his sister to create the House of M, he abandoned X-Factor, and he stole the Inhumans' Terrigen Mists to repower the mutant population, after himself, of course.
3 HULK
While most of the entries on this list feature members of the Avengers who have betrayed their teammates, it sometimes works the other way as well. Prior to the events of the Planet Hulk storyline, the Avengers (most notably Iron Man and the rest of the Illuminati) create a plan to rid the Earth of an ongoing threat - the Incredible Hulk.
Once a founding member of the Avengers, Hulk had himself turned on the team a few times over the years. After the Hulk's most recent outburst, Iron Man and the Illuminati decided to shoot Hulk into space to rid themselves of the bother. Eventually, Hulk would return to Earth and retaliate against Iron Man and the Avengers for their betrayal.
2 SCARLET WITCH
Since we've already discussed Wanda's brother Pietro and his many betrayals over the years, it should come as no surprise that Scarlet Witch has also been a frequent turncoat in the Avengers. Wanda's mutant abilities and mental stability were affected over the years by her connection to magic, which culminated in a series of betrayals to both the Avengers and her fellow mutants.
Following years of hardships like magically creating and then losing her twin children, Wanda eventually snapped and began to subtly sabotage her Avengers teammates before outright forcing She-Hulk to rip the Vision in half, or conjuring a Kree Warship that killed Hawkeye. During House of M, Wanda would nearly wipe out mutantkind with one powerful phrase - "No More Mutants."
1 CAPTAIN AMERICA
The vilest scumbag to have ever turned on the Avengers comes from one of the greatest heroes to ever serve with the team - Captain America. Leading up to the Secret Empire storyline, it was revealed that Steve Rogers/Captain America was actually a secret agent of HYDRA, and had been for years.
Of course, this heel turn was revealed to be due to the machinations of Red Skull and the Cosmic Cube entity known as Kobik, though that didn't stop "Hydra Cap" and HYDRA from taking over. Only the return of the real Steve Rogers was able to stop the Secret Empire and Hydra Cap, but the team and the Marvel Universe is still dealing with the ramifications of this crippling betrayal.