MCU: This Avenger Has Switched Sides Nearly as Often as Loki but for a Completely Different Reason

The Avengers might currently be in something of a transitional period. Certainly, Earth’s Mightiest Heroes deserve a break after Avengers: Endgame. Likewise, the Marvel Cinematic Universe needs time to reassess and recalibrate. After all, Loki isn’t the only MCU character with a shaky allegiance to good or evil. In fact, one Avenger flip-flops nearly as much.

The cast of 'Avengers: Infinity War'
The cast of ‘Avengers: Infinity War’ | Charley Gallay/Getty Images for Disney

The heroes and villains of the MCU are known for shifting alliances

With more than 20 movies, the MCU has given its characters plenty of room to grow and evolve. So fans have seen heroes go rogue, and villains find their way to the light. Even within the core Avengers, nearly all of them have confronted their own inner darkness.

Black Widow (Scarlett Johansson) was a Russian assassin before S.H.I.E.L.D. recruited her. Iron Man (Robert Downey Jr.) unknowingly contributed to terrorism through Stark Industries. Following the death of his family, Hawkeye (Jeremy Renner) became a violent vigilante known as Ronin. And Hulk (Mark Ruffalo) — well, you wouldn’t like him when he’s angry.

Conversely, a few characters who started out as villains have shown a lot more dimension in subsequent appearances. Guardians of the Galaxy’s Nebula (Karen Gillan) turned from Thanos’ (Josh Brolin) warrior to a full-on Avenger. And Scarlet Witch (Elizabeth Olsen) joined up with Ultron (James Spader) to destroy the Avengers before switching sides.

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Loki is the best known, but another character also has a very dark past

Tom Hiddleston’s Loki has become the go-to example of an MCU character who has expertly shifted between hero and villain. Throughout his appearances, Loki fluctuates between teaming up with Thor (Chris Hemsworth) and trying to destroy him. As the god of mischief, we’d expect nothing less.

But another character is just as unreliable. And it’s not even his fault.

When audiences meet Bucky Barnes (Sebastian Stan), he’s the loyal, good-hearted friend of Steve Rogers (Chris Evans). After seemingly falling to his death, Bucky emerges decades later as the deadly Winter Soldier. All that time, he was the brainwashed expert assassin for HYDRA. Captain America: Civil War even reveals he killed Tony Stark’s parents back in the 1990s.

Just within that third MCU Captain America film, Bucky goes back and forth between hero and villain. Of course, unlike Loki, Bucky has no choice. He’s at the mercy of Zemo (Daniel Brühl) and retreats to Wakanda for reprogramming. From that point on, Bucky is back in control. Hopefully, The Falcon and the Winter Soldier allows him to stay with the good guys.

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Which hero could turn against the Avengers in the upcoming movies?

Even if Bucky does remain loyal to his fellow MCU heroes, perhaps other characters will take a dark turn. If power corrupts, then heroes like Captain Marvel (Brie Larson), Doctor Strange (Benedict Cumberbatch), and Scarlet Witch could easily become the next Big Bad.

The biggest theory MCU fans have been mulling is regarding Hulk. The character has the most untapped potential to become a villain in Phase 4. Especially now that Bruce Banner has combined the brains and the brawn, an evil Hulk could be unstoppable if Marvel Studios goes that route.