Yet, even with this dedication to the source, Marvel Studios has occasionally strayed off course. There have been moments when the MCU introduced characters from the comics only to significantly rework them, leaving fans bewildered at best, and frustrated at worst. Some of these characters were reshaped to fit into an already well-established MCU, while others were villains reimagined to drive specific plot points. Despite the intentions behind these changes, certain alterations have been so drastic that they remain a point of contention among fans.

One of the most notable missteps involved the Mandarin, Iron Man’s arch-nemesis from the comics. The challenge with bringing the Mandarin to life lay in avoiding the offensive Asian stereotypes that plagued his original depiction. When Ben Kingsley was cast, early glimpses suggested a fresh take: a foreign terrorist determined to topple Tony Stark, symbolizing the excesses of the American Empire. It seemed like a promising adaptation that could respect the character’s roots while updating him for modern audiences.

Fortunately, Marvel learned from this misstep. In “Shang-Chi and the Legend of the Ten Rings,” the real Mandarin, played by Tony Leung, was unveiled, allowing the character to be portrayed with the depth and nuance he deserved. Despite the initial backlash, Trevor Slattery’s character will make a return in the Disney+ series “Wonder Man,” hinting at Marvel’s continued interest in exploring its complex character roster.

The MCU has generally succeeded in translating its iconic villains from page to screen, with Thanos, Kang, and Ultron being notable examples. However, there have been exceptions, like the disappointing adaptation of Taskmaster. This character, a favorite among comic book fans, unfortunately failed to make a lasting impact in the cinematic world, leaving enthusiasts longing for a portrayal that truly honors the original character’s legacy.

Thankfully, Marvel eventually wised up. In “Shang-Chi and the Legend of the Ten Rings,” we discover that Killian was a wannabe — and the true villain, played by Tony Leung, was the real Mandarin. Despite the negative reaction to Slattery, though, the character will return in the Disney+ series “Wonder Man.”

The Avengers have plenty of iconic baddies in the comics, from Thanos and Kang to Ultron and beyond. So far, Marvel has gotten them mostly right in the MCU, with a few notable exceptions on this list. While Kang proved largely disappointing, it wasn’t because the character was changed all that much. In that category is Taskmaster, a character beloved in the pages of “The Avengers” but whose appearance on screen has been nothing short of a disastrous disappointment for fans.

In the comics, Taskmaster is Tony Masters, a man with a nearly supernatural ability to mimic the fighting style of anyone he sees. As a result, he carries a bow and arrow like Hawkeye, a shield like Captain America, and a sword like the Swordsman. And with them, he became one of the Avengers greatest and most persistent foes. Unfortunately, the character was totally rewritten for “Black Widow,” becoming a former agent of the Black Widow program named Antonia Dreykov (Olga Kurylenko). Her memory has been wiped, and she is a flunky of her father, who runs the mysterious Red Room that runs Russia’s program for female mercenary agents.

Though her powers are largely the same, and her outfit was a relatively faithful translation from the comics, turning such an iconic villain into a mere henchman was more than fans could stomach. She gets barely any dialogue in the film, too. But even worse, when her memory returned, she was due to return in “Thunderbolts,” and fans were hopeful she could be redeemed — until she was killed off in the film’s first 20 minutes.

Another of the Avengers’ biggest baddies in the comics is Baron Zemo. It was Heinrich Zemo who faced off initially with Captain America in World War II; and in the modern day, it was Heinrich’s son, Helmut Zemo, who inherited the villainous mantle and became an ongoing threat to the Avengers. Fans clamoring for Zemo were disappointed, however, when he turned up in the MCU in “Captain America: Civil War.” Far from the powerful nobleman who assembled his own team of villains to battle the Avengers, Zemo in the MCU was a disgruntled Sokovian played by Daniel Brühl, bitter that the Avengers destroyed his country and killed his family during the events of “Avengers: Age of Ultron.”

Zemo, rather than assembling a version of the Masters of Evil, instead broke the Winter Soldier (Sebastian Stan) out of imprisonment and used his Hydra brainwashing to turn the Avengers against one another. Though the movie was excellent, and Brühl was solid as a very different version of Zemo, it wasn’t the Baron Zemo fans were hoping for. And like Taskmaster, when the character returned in the Disney+ series “Falcon and the Winter Soldier,” he’s even further from his comic book roots. There, he was given a release from prison to help Sam Wilson and Bucky on a new mission, and is more often used as comic relief than as a terrifying menace to our heroes as he should have been.

When the Marvel Cinematic Universe’s earliest movies were announced in 2006, “Ant-Man” was among them. The character, whose civilian identity is Hank Pym, was a founding member of the Avengers after all, and so it made sense to feature him in his own movie ahead of a big team-up. Unfortunately, he was nowhere to be found in the first two “Avengers” movies and didn’t debut until 2015. But Ant-Man in the MCU wasn’t Hank Pym, but Scott Lang (Paul Rudd), who was the second person to hold the mantle in the comics. Instead, Pym was a supporting player in the film, and was an older man who was long retired, played by Hollywood legend Michael Douglas.

In the film, we learn that Hank Pym was the original Ant-Man back in the early days of SHIELD and used his shrinking technology to go on covert missions for the agency alongside his wife, Janet Pym, the Wasp (played by Michelle Pfeiffer in the sequel). Instead of being a hero on his own adventures, Pym was an aging scientist who had to recruit a younger man to take the Ant-Man suit when a villain emerged to steal his technology.

Make no mistake, Pym’s portrayal is fine, and it is a good concept for where the character would be as an older man. But that’s not the Hank Pym we wanted to see; and as of now, all we’ve gotten is a couple of fun flashbacks — much to the chagrin of longtime readers of the original “Avengers” comics.

Despite four “Fantastic Four” films, including one in the MCU, audiences have still really only seen two of the team’s biggest rivals as major threats: Galactus and Doctor Doom. But in 2023, Marvel released a dramatic miniseries based on one of the biggest intra-company crossover event stories, “Secret Invasion” — and its villain was, apparently, going to be the Super-Skrull. In the comics, Kl’rt the Super-Skrull is an alien Skrull who comes to Earth and copies the powers of the Fantastic Four to become a deadly villain capable of defeating the toughest of superheroes.

Landing with a major thud, “Secret Invasion” was roasted by fans as a pale imitation of the comic book event, and a big reason why was the awful disappointment of the Super-Skrull in the series. Because in the MCU, they’ve radically altered the character, combining him with another Skrull villain, Gravik. In the Disney+ series, he leads a group of rebel Skrull who steal samples of DNA from Earth’s mightiest heroes — including Groot, Captain Marvel, and the Hulk — to become a superpowered terrorist capable of wiping out entire armies.

The problem, of course, is that Gravik’s version of the Super-Skrull bears little resemblance to the character in the comics, and the Fantastic Four weren’t even a part of the MCU at the point he was introduced. He doesn’t have Reed Richards’ stretching powers or Sue’s invisibility, nor Johnny Storm’s flaming body or the Thing’s rocky skin. In that sense, he is, like the miniseries, a pale imitation.