Not every hero in theMarvel Cinematic Universehas been lucky enough to make a good first impression with their debut. Over the last 17 years, Marvel Studios has adapted dozens of Marvel Comics' most complex, interesting and powerful characters into live-action, but introducing so many characters to the MCU means not all of them have been given the attention they deserve. Some have unfortunately been misrepresented in even their first appearance in the MCU, so some of the franchise’s most iconic heroes have had pretty poor debuts.
Many of the franchise’s best heroes have had some of the mostmemorable and powerful debuts in the MCU, including the likes of Tony Stark’s Iron Man, the Guardians of the Galaxy, Wanda Maximoff’s Scarlet Witch and Peter Parker’s Spider-Man.Others, however, haven’t been so lucky, and this includes several of the franchise’s central heroes, such as Hawkeye and Black Widow. Many smaller-scale heroes have also been done dirty, including formidable recent additions such as G’iah and Starfox, but Marvel Studios could still make these heroes mean more than their disappointing debuts suggest.
10G’iah
Emilia Clarke Debuted As G’iah In Secret Invasion (2023)
Despite being Samuel L. Jackson’s first solo series as the former Director of SHIELD, Nick Fury,2023’sSecret Invasionbecame one of the MCU’s lowest-rated projects due to its slow pace, too-grounded narrative and lack of faithfulnessto Marvel Comics' iconicSecret Invasionevent. One of the most exciting aspects ofSecret Invasionwas the introduction of Emilia Clarke asTalos' Skrull daughter, G’iah, but her debut didn’t have the impact many hoped it would. This became even weirder after G’iah obtained her own superpowers inSecret Invasion’sfinale, becoming the MCU’s Super Skrull.
G’iah was enhanced with the powers of some of the MCU’s strongest heroes and villains who spilled blood duringAvengers: Endgame’sBattle of Earth, as she was exposed to theDNA in the Harvest. This makes G’iah one of the most stupidly-overpowered characters in the MCU, but the poor visual effects and lackluster CGI battle between her and Gravik inSecret Invasion’sfinale meant her gaining these powers was unoriginal and forgettable.It would be great to see G’iah return to give her disappointing debut more weight, but Emilia Clarke’s MCU future hasn’t been confirmed.
9Reed Richards' Mister Fantastic
John Krasinski Debuted As Reed Richards' Mister Fantastic In Doctor Strange In The Multiverse Of Madness (2022)
Pedro Pascal is set to make his MCU debut as the franchise’s official version ofReed Richards in 2025’sThe Fantastic Four: First Steps, but he won’t be the first Mister Fantastic seen in the MCU.The OfficeandA Quiet PlacestarJohn Krasinski appeared as Earth-838’s Reed Richards inDoctor Strange in the Multiverse of Madness, where he was introduced as the leader of the Fantastic Four and a member of the Illuminati. Krasinski had been a popular fan-cast for the iconic role, butMultiverse of Madnessproved that this casting perhaps wouldn’t actually work in the MCU.
John Krasinksi’s version of Mister Fantastic was a bit dull, even though he delivered some of the most intriguing and informative lines in the entire Multiverse Saga. Soon after his debut, he was also unceremoniously murdered by Wanda Maximoff’s Scarlet Witch. The fact that he underestimated the Scarlet Witch, directly caused Black Bolt’s death and was in turn spaghettified by the magic-wielding villain meansKrasinski’s Mister Fantastichad a pretty awful MCU debut. Pedro Pascal’s Reed Richards will surely have a brighter future in the franchise.
8Skaar
Wil Deusner Debuted As Skaar In She-Hulk: Attorney At Law (2022)
It was great to see Mark Ruffalo’s Bruce Banner return alongside his cousin,Tatiana Maslany’s Jennifer Walters, in 2022’sShe-Hulk: Attorney at Law, even if he only made a brief appearance in the Phase 4 series. Banner’s Smart Hulk had a key role in training Walters' She-Hulk in the series premiere, but then traveled into space to return to Sakaar.He came back to Earth inShe-Hulk: Attorney at Law’sfinale, which gave him the opportunity to introduce his mysterious son, Skaar, to the MCU, played with no speaking lines byStargirlactor Wil Deusner.
The first version of Skaar introduced to Marvel Comics was an alternate iteration in 2007’sWhat If? Planet Hulk #1, while the Earth-616 version made his first appearance in 2008’sWorld War Hulk #5, created by Greg Pak and John Romita Jr..
Marvel Comics' Skaar is the son of the Hulk and Caiera, the latter’s death spurring the former to return to Earth and embark on the iconicWorld War Hulkstoryline. Skaar’s debut could have kick-started a possibleMCU adaptation ofWorld War Hulk, but Bruce Banner returned in the series finale still in high spirits, andnothing has been heard from either Banner or Skaar in the three years since. It’s a shame that nothing has come of Skaar’s insignificant MCU debut, and there are hopes it’ll be resolved inAvengers: DoomsdayorSecret Wars.
7Adam Warlock
Will Poulter Debuted As Adam Warlock In Guardians Of The Galaxy Vol. 3 (2023)
It was a controversial decision for Marvel Studios and James Gunn to castWill Poulter as Adam Warlockahead of his debut in 2023’sGuardians of the Galaxy Vol. 3, and the jury’s still out on whether this unorthodox casting choice actually paid off.Adam Warlock is viewed as one of Marvel Comics' most powerful heroes, having been central in Marvel’s cosmic storylines since his creation in 1967. He is god-like, immortal and tapped into all cosmic energies, and while this level of power was teased in the MCU’s Phase 5, it wasn’t quite put on display fully.
Now, this might not be an issue, asJames Gunn confirmed that Adam Warlock was supposed to be baby-like inGuardians of the Galaxy Vol. 3. It would be fantastic to see him grow and develop in the MCU’s future, but Will Poulter hasn’t yet been confirmed to be reprising the role, and it’s unclear exactly when he could.Adam Warlock joined the Guardians of the Galaxy teamat the end ofVol. 3, but the future of this new line-up isn’t certain, which means Adam Warlock might always be a comedic, baby-like villain-turned-hero, which is pretty disappointing.
6Clint Barton’s Hawkeye
Jeremy Renner Debuted As Clint Barton’s Hawkeye In Thor (2011)
Jeremy Renner’s Clint Barton has gone on to become one of the MCU’s most crucial heroes as expert marksman Hawkeye, even mentoring the next generation of superheroes in his first solo series in Phase 4. However, his start in the franchise left a lot to be desired. Renner first appeared asHawkeye in 2011’sThor, where he debuted as a SHIELD soldier tasked with keeping a watchful eye over Chris Hemsworth’s God of Thunder during his attempt to reclaim Mjolnir from its New Mexico crater. Barton’s role inThorset up his return, but even this fell flat.
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After having very little to do inThor, Jeremy Renner returned in 2012’sThe Avengers, but was again wasted as he was immediately put under Loki’s control. This neglect was so obvious that evenJeremy Renner asked for Clint Barton to be killed offduringThe Avengers, though we are now grateful that this didn’t come to pass.Hawkeye’s MCU career afterThorandThe Avengershas been incredible to watch, and his next steps as Kate Bishop’s mentor and perhaps a returning Avenger are very exciting, albeit yet to be confirmed.
5Ruth Bat-Seraph
Shira Haas Debuted As Ruth Bat-Seraph In Captain America: Brave New World (2025)
Shira Haas made her MCU debut in 2025’sCaptain America: Brave New Worldas former Black Widow assassin and United States government Head of Security Ruth Bat-Seraph. Unfortunately, while her first appearance should have been full of power, action and intensity,she was rendered lifeless and dull by the changes that Marvel Studios made to the comic character. In Marvel Comics, Ruth Bat-Seraph is otherwise known as themutant superhero Sabra, but the character’s mutant identity and subsequent superpowers were completely removed inBrave New World.
Reshoots and production changes for Anthony Mackie’s theatrical debut as Captain America also limitedShira Haas' role inBrave New World, which meant that Ruth Bat-Seraph had very little to do in the movie. The character was stripped of anything that made her interesting, andBrave New Worldcould have easily told its story without her involvement, which is never a good sign.It’s a shame that Ruth Bat-Seraph wasn’t handled with more care in the MCU, as she could have been a key member of the franchise’s upcoming mutant stories, but this now seems unlikely.
4Danny Rand’s Iron Fist
Finn Jones Debuted As Danny Rand’s Iron Fist In Iron Fist (2017)
Finn Jones' Danny Randhas been considered the weakest link in Marvel’s Defenders Saga ever since he first appeared in 2017’sIron Fistseason 1. The legend of the Iron Fist was crucial to the story of the Hand and the narrative of the 2017 crossover miniseries,The Defenders, so it was essential that Danny Rand see some development beforehand. Unfortunately,Jones' lack of proper fight training, a slow-burning narrative and not much Iron Fist action made Danny Rand’s debut in the Defenders Saga lackluster.
Marvel Studios confirmed the Defenders Saga to be canon to the MCU’s main continuity in early 2024. This allowed several characters fromDaredevilto return inDaredevil: Born Again, though the other Defenders, Finn Jones' Danny Rand, Krysten Ritter’s Jessica Jones and Mike Colter’s Luke Cage, haven’t yet been confirmed to be returning.
While Finn Jones might have been a great casting choice for the role of Danny Rand in live-action,it was the production, narrative issues, pacing and script of theIron Fistseries that meant his debut wasn’t as good as it could’ve been. Jones has recently revealed he’d be up for returning to the role in the MCU’s future, which creates the opportunity for the Defenders Saga mistakes to be fixed. While his initial debut might have been disappointing, there are hopes that his reintroduction could finally do theIron Fist justice in the MCU.
3Pietro Maximoff’s Quicksilver
Aaron Taylor-Johnson Debuted As Pietro Maximoff’s Quicksilver In Captain America: The Winter Soldier (2014)
Quicksilver is one of the most iconic and notable characters ever to be introduced to Marvel Comics, so Aaron Taylor-Johnson’s debut as the speeding hero inAvengers: Age of Ultronwas incredibly exciting. Taylor-Johnson made his first cameo appearance alongside Elizabeth Olsen, who playedQuicksilver’s sister, Wanda Maximoff’s Scarlet Witch, in the mid-credits scene ofCaptain America: The Winter Soldier, which teased a huge future for them both as the MCU’s first “Miracles.” Unfortunately, the future had different ideas for Pietro Maximoff, as he was shockingly killed off inAge of Ultron.
Aaron Taylor-Johnson made his debut as Quicksilver shortly after Evan Peters portrayed a mutant version of the same character in 20th Century Fox’sX-Menfranchise, which drew unfortunate comparisons between the pair.Peters has been praised as the most successful Quicksilver, perhaps due to his longevity, while many want to see Taylor-Johnson’s version return. His sudden and inexplicable death at the hands of Ultron a decade ago removed one of the MCU’s most exciting characters before he ever really had a chance to do anything, which is a huge shame.
2Natasha Romanoff’s Black Widow
Scarlett Johansson Debuted As Natasha Romanoff’s Black Widow In Iron Man 2 (2010)
Natasha Romanoff’s Black Widowwas featured as one of the most important MCU heroes in all of her appearances between her debut in 2010’sIron Man 2and her posthumous solo debut in 2021’sBlack Widow. Despite her prominence,Romanoff was often neglected, ignored, sidelined and wasted by Marvel Studios, and this is perhaps most evident in her first appearance back in Phase 1.Iron Man 2introduced Romanoff as a SHIELD spy infiltrating Stark Industries to keep an eye on Tony Stark, but theIron Mansequel did not treat Black Widow with the respect she deserved.
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Iron Man 2sexualized Natasha Romanoff and made her the subject of characters' misogyny, whether that be by having Happy Hogan belittle her in the boxing ring, having Tony Stark search for lewd images of her online, or having Happy struggle to keep his eyes on the road when she changed her outfit in the car. This was an embarrassment, and it would have been better for Black Widow to debut without this noise. Natasha Romanoff did a good job at breaking free of this quickly, but it’s still not a wonderful way for her MCU career to begin.
1Eros' Starfox
Harry Styles Debuted As Eros' Starfox In Eternals (2021)
2021’sEternalsbecame one of the MCU’s most divisive projects after its release in Phase 4, withmany criticizing the movie’s attempt to introduce so many new heroes, as this meant that none of the ten main characters really got the development they deserved. This was made even worse inEternals’mid-credits scene, which introduced yet another Eternal in the form ofHarry Styles' Eros, a.k.a. Starfox. The former One Direction star made his MCU debut promising to help Thena, Makkari and Druig track down their missing friends, but this tease has led to absolutely nothing.
Harry Styles' Eros was introduced as the brother of the Mad Titan, Thanos, who collected the six Infinity Stones and wiped out half the universe’s population inAvengers: Infinity War. Eros and Thanos' returns to the MCU are paramount to explain exactly what their connection is, but neither have been confirmed to be coming back.
Eternals’poor performance in Phase 4 has meant that Marvel Studios has seemingly shelved or canceled any plans for the titular team to return. This is despite the fact thatEternalshas recently been receiving more retrospective admiration. The movie’s mid-and-post-credits scenes set up some exciting stories for the future of theMarvel Cinematic Universe, but neither have been resolved, which makes Harry Styles' debut as Eros seem meaningless and insignificant, when it could have actually been game-changing for the franchise and themythology of the Eternals and Thanos, too.
