The Avengers team and its changing members have been shown to have a vast range of powers between them, but there are still a number of comic book abilities that have either not been incorporated into the MCU characters or are yet to be properly explored.
Whether they would change the world of the movies or highlight aspects of a character already explored, these comic book powers could truly shake things up for Earth's Mightiest Heroes and their future missions. With the recently released What If...? series providing glimpses into alternate realities, there are ways for these powers to be explored even when they concern characters now gone from the movie's main timeline.
Captain America: Slowed Aging
Steve Rogers (Chris Evans) may have retired from the Avengers team after some time-travelling high jinks during Avengers: Endgame left him as an elderly man in the present day, but in the comics, Captain America's exposure to the super-soldier serum means the speed at which he ages is greatly slowed.
Although this somewhat accounts for Cap's MCU survival during the years he spent frozen, other aspects of this ability have not made their way on screen. This power could still be explored in some capacity given Steve's current unknown status, or else in an alternate universe as showcased in What If...?, and serve to show the long-lasting effects of Dr. Erskine's experimental serum.
The Hulk: Resistance To Psychic Control
As a being with incredible strength and durability, Bruce Banner's (Mark Ruffalo) alter-ego is usually not associated with mind-based powers, but on multiple occasions in the comics the Hulk has come up against those who wield psychic powers and shown resistance to their control.
This is in direct contrast to the MCU Hulk's response, as seen when he comes up against the Scarlet Witch's (Elizabeth Olsen) machinations in Avengers: Age of Ultron. While there are a number of ways in which the comic book Hulk is the strongest Avenger, seeing his movie counterpart develop an affinity for resisting this kind of control in response to his history with Wanda would make for a satisfying arc, while echoing Bruce's own carefully built mental fortitude.
Black Widow: Gifted Hypnotist
Natasha Romanoff (Scarlett Johansson) possesses a plethora of skills as Black Widow, but the movies of the MCU have not shown her abilities as a gifted hypnotist. She uses a combination of methods in order to effect her target's mind, and is even able to have an impact on their thoughts, memories, and personality traits.
Given that the Black Widow movie explored the damaging effects of mind control on Natasha and the other Widows, it makes sense that the MCU's Natasha has not been shown to use this morally grey power, but its implementation in later stories, even if it was as one of Yelena's (Florence Pugh) abilities, could highlight the complexity of how the Widow's feel able use their training.
Scarlet Witch: Nexus Being
Scarlet Witch isn't always in control of her powers, but nevertheless she can use them to impose massive changes on the reality of her surroundings and other people, the extent of which is most fully explored in WandaVision. The comics go one step further, though, positioning her as a nexus being, a person whose mere existence effects reality and acts as an anchor between alternate timelines.
Given the MCU's recent focus on timelines, as seen in Loki and What If...?, alongside Wanda's confirmed presence in the upcoming Doctor Strange in the Multiverse of Madness, it stands to reason that this ability may yet be explored. Furthering Wanda's connection to the multiverse in this way would allow a greater involvement of the character going forward, with the potential to turn the world of the MCU on its head.
Sam Wilson: Telepathic Link To Birds
Sam Wilson's (Anthony Mackie) movie sidekick Redwing may be a drone, but in the comics he is actually a real falcon that Sam trained. In fact, many Marvel Comics featuring Sam Wilson expand upon the hero's connection with his namesake to a connection with all birds, giving him an empathic and telepathic link with them.
By using this power Sam can see through the eyes of birds he connect to, which comes in handy when he needs to scan a vast area or search for something specific. Given the MCU's commitment to remaining a little more grounded - at least when compared to the comics - this change does make sense, but with Sam now taking on the mantle of Captain America, a small link to birds could keep him tied to his origins as the Falcon.
Thor: Inter-dimensional Teleportation
Thor (Chris Hemsworth) often makes use of Heimdall (Idris Elba) and the Bifröst bridge in early MCU movies in order to travel to-and-from worlds, but the introduction of his new weapon Stormbreaker in Avengers: Infinity War grants him the power to access that method of transportation himself. In the comics, his hammer Mjölnir also has the ability to teleport Thor, with the added capability that it can travel inter-dimensionally.
As Thor joined the Guardians of the Galaxy at the conclusion of Endgame, having a weapon that is able to travel across such boundaries would prove highly useful in his new line of work. Not only that, but having the chance to pass through realities could bring him face to face once more with his brother, Loki (Tom Hiddleston), or any number of Loki variants.
Iron Man: Extremis Powers
As a character within the MCU who's often the smartest person in the room, Tony Stark (Robert Downey Jr.) faced many challenges during his time as Iron Man, including coming up against the experimental treatment Extremis in Iron Man 3.
Tony may not be afflicted with the serum in this movie, but that's not the case in one comic arc, where it grants him a host of new abilities including an enhanced healing factor and technopathy which he can use to interface with all kinds of technology. Plenty of alternate versions of Tony appear in What If...?, and seeing how his life would change had he been influenced by Extremis would make for a compelling narrative.
Hawkeye: Goliath Powers
The MCU's Clint Barton (Jeremy Renner), AKA Hawkeye is shown to have skills solely associated with archery and the precision that comes alongside it. In the comics, however, Clint does at one point use Pym particles to become the hero Goliath, gaining abilities that mirror Ant-Man's.
With the upcoming introduction of Kate Bishop (Hailee Steinfeld) to the MCU in Hawkeye, Clint's future as the archer may be coming to a close, but were the show to explore his interest in Pym technology, he could have a future under the name of another hero, and explore his desire to try something new.
Nebula: Disguise Appearance
Nebula (Karen Gillan) has been through one of the most evident character arcs over the course of her MCU appearances, going from villain to antihero, to member of the Avengers as seen in Endgame. All the while, though, the powers focused on have been her superhuman fighting abilities, whereas in the comics, Nebula is also able to completely disguise her appearance.
This ability would have obviously come in handy for Nebula when she worked as an assassin, but still has its uses for her in her current position as a member of the Guardians, where travelling from world to world can mean its necessary to blend in with the locals.
Spider-Man: Spider-Sense
Although Peter Parker's (Tom Holland) precognitive ability to sense incoming danger, most often called his Spider-Sense, has been included in the MCU, jokingly referred to as his "Peter Tingle" by Aunt May, its capabilities have not been fully shown.
The comics show that this sense also helps Peter to navigate if he is ever unable to see or hear. Expanding the on screen ability in this way would help Peter to thrive in a wider set of circumstances, and may prove useful in the upcoming Spider-Man: No Way Home.