Marvel Studios is regarded as a pioneer in connecting various story arcs within a unified cinematic universe. From standalone films to a unique ensemble of superheroes consisting of six members, the MCU has introduced hundreds of characters across diverse settings, dimensions, and realities. The scope of the MCU is expanding day by day, with increasing depth.
However, over the 15-year journey, there have been numerous instances where Marvel Studios overlooked details that could create intriguing narrative possibilities for the future.
The Collector’s Backstory

Benicio del Toro has portrayed Taneleer Tivan/The Collector with remarkable excellence. The character first appeared in the post-credit scene of Thor: The Dark World, showcasing his vast collection of powerful artifacts, including Hela’s sword and the Aether, one of the six Infinity Stones.
In reality, the Collector has nearly gathered the second Infinity Stone, and his unique conversational style makes him a distinct and intriguing character, hinting at many unexpected developments in the future. However, over time, it seems that the Collector did not play a significant role in the overarching MCU narrative. Once the focus shifted to Thanos in Infinity War, the Collector was quickly forgotten by Marvel Studios.
Many fans believe that this character was left out during Thanos’s conquest. Nevertheless, the short film Guardians of the Galaxy Holiday Special confirmed that the Collector is still alive. He even goes on to sell the Knowhere space station to the Guardians.
In an episode of the animated series What If…?, viewers gained deeper insight into the Collector’s formidable powers. Additionally, with a significant presence in the Disney California Adventure ride, Guardians of the Galaxy: Mission Breakout, the character still offers numerous angles for exploration. The Collector’s backstory contains many intriguing details that could potentially play a role in future MCU projects.
Sonny Birch’s Objectives

Ant-Man & The Wasp introduced a new character named Sonny Birch, played by Walton Goggins. Throughout the film, this character continuously pursued Hank Pym’s experimental lab to find an undisclosed target. To date, this storyline has not been explored by Marvel Studios, as Ant-Man & The Wasp: Quantumania shifted focus to a new narrative entirely.
This can also be seen as an opportunity for Marvel Studios to revisit significant characters like Justin Hammer (played by Sam Rockwell), the Power Broker, who appeared in the series The Falcon & The Winter Soldier, and even Kingpin, who has appeared in the series Hawkeye and is set to feature in upcoming projects like Daredevil: Born Again or Echo. There are plenty of choices for Marvel Studios, and they could potentially resolve this storyline surrounding characters like Captain America: New World Order or Armor Wars.
Lady Sif

Lady Sif first appeared as a fierce warrior in Asgard, serving as one of Thor’s closest allies, often fighting alongside him since their youth. Sif became particularly prominent after Thor was banished to Earth, where she teamed up with the new king, Loki, to assist her friend. Following this, she continued to participate in battles against the Dark Elf in Thor: The Dark World, but later disappeared mysteriously when Thor faced Hela in Ragnarok.
Sif returned in Thor: Love and Thunder, but her role was notably minor compared to her earlier appearances in Thor’s solo films. Marvel Studios also did not provide any explanations regarding what Sif had been doing during the timeline between The Dark World and Love and Thunder. In her latest appearance on the big screen, Sif is training young warriors in New Asgard.
Once a character with immense potential upon her introduction into the MCU, it seems that Marvel Studios has yet to truly delve into Sif’s storyline. She could certainly appear in various Disney+ series, such as She-Hulk: Attorney at Law, where she hinted at her connection with Jennifer Walters.
Mitchell Carson

Mitchell Carson is an agent who operates under the guise of S.H.I.E.L.D but is actually working for HYDRA. He first appeared in the 1980s, seeking a way to replicate Pym particles alongside Howard Stark and Peggy Carter. Many years later, when preparing to buy back the Yellowjacket suit to supply Pym particles to HYDRA, Carson was discovered and thwarted by Ant-Man.
However, what happened to Carson and the briefcase containing Pym particles remains a mystery. Marvel Studios has yet to provide a concrete answer to this detail, even though a scene was cut from the theatrical release where he was apprehended.
A.I.M of Aldrich Killian

Iron Man 3 stirred significant controversy upon its release, but it has since been widely recognized and has become a crucial part of the MCU’s overarching narrative. Many details in this film, including the Mandarin and the Ten Rings, have resurfaced in other Marvel Studios projects. However, the A.I.M company of Aldrich Killian has remained largely untouched.
Killian is one of the notable villains that have slipped through the cracks of the superheroes, specifically Tony Stark in this case. Once a brilliant mind, he founded A.I.M to execute dangerous Extremis experiments (which included a group of enhanced soldiers). In the comics, A.I.M is a major organization often linked with various supervillains to develop advanced technology while also clashing with organizations like S.H.I.E.L.D or other superheroes.
As such, A.I.M could play a vital role in various upcoming projects, particularly in Disney+ series like Daredevil: Born Again.
Mordo

Doctor Strange established Mordo as a key antagonist against the superhero, directly confirming that he became a key threat in opposition to Stephen Strange. Following this, the after-credit scene hinted at his dark plan to eliminate all other sorcerers. However, Mordo (from Earth-616) did not appear in Doctor Strange in the Multiverse of Madness.
The version seen in this film comes from Earth-838 and is a member of the Illuminati. When facing off against Strange, he mentioned that the Mordo from Earth-616 is actively seeking to eliminate him, suggesting that these two characters have crossed paths before but were not depicted in Marvel Studios productions. According to initial plans, Scarlet Witch was set to confront Mordo at the beginning of Doctor Strange in the Multiverse of Madness. However, this scene was later cut, meaning that Mordo remains an active threat still lurking in Earth-616.
With Doctor Strange facing larger issues related to multiversal threats and dimensions, the likelihood of Mordo returning in Doctor Strange 3 (if it is produced) is quite low. However, this character could still feature prominently in the next magic-themed series from the MCU – Agatha: Coven of Chaos.
Tony Stark’s Technology Replicas

Many details regarding technology were introduced when Tony Stark faced off against Whiplash in Iron Man 2. Stark was regarded as a national hero; however, Justin Hammer failed to replicate the technology of Iron Man. Even other countries were looking for ways to utilize Tony’s technology for their own military purposes. Stark ensured that his technology was well-protected during the decade that followed, but this period also led to numerous loopholes in his operations.
Ten years have passed, and the question arises: what advanced replicas of Tony Stark’s technology have been developed? The answer to this could potentially be explored in the upcoming film Armor Wars. This project will focus on War Machine’s efforts to deal with the fallout from Tony Stark’s technology appearing on the global stage. The “hint” was first introduced in the post-credit scene of The Falcon & The Winter Soldier, where Sharon Carter revealed that her organization had access to Stark Tech’s resources, including unmanned aerial vehicles.
Other projects like Secret Invasion and Thunderbolts may also play a role in this narrative, providing an opportunity for Marvel Studios to introduce iconic characters associated with dangerous technology, such as Titanium Man, Crimson Dynamo, or Ezekiel Stane.
Scorpion

The after-credit scene of Spider-Man: Homecoming revealed the character Mac Gargan/Scorpion, played by Michael Mando. Prior to this, Gargan had appeared in this film as a criminal who had previously failed to assassinate Spider-Man. Additionally, Vulture and other characters were executing a project called “The Gargan Tail” (Gargan’s alias). All of these details serve as a foundation for Gargan’s potential transformation into the Scorpion in the future. The after-credit scene also hinted at this character’s interaction with Vulture in prison and their failed collaboration to eliminate Spider-Man.
Since Homecoming, Spider-Man has continued through various adventures in the MCU, but there has been no trace of Scorpion in the meantime. The after-credit scene of No Way Home indicates that this character may be a significant player in a future solo film for Spider-Man, yet so far, he remains in the shadows. Nonetheless, the likelihood of Scorpion reappearing in the MCU is considerable, as Spider-Man will inevitably face off against villainous characters in the Marvel universe in the near future. Following this emotional journey, the next installment featuring Peter Parker is likely to have a smaller scale and would be entirely fitting for the introduction of villains like Scorpion.
Source: Movieweb, Marvel Studios