In the Marvel Cinematic Universe, it has been established that certain powerful objects can only be wielded by beings on extraordinary strength. This was shown by The Collector in Guardians of the Galaxy when various celestial beings failed to properly utilize the Power Stone as it overwhelmed them. Star-Lord was said to only survive the ordeal due to his part-Celestial body.
For objects not relating to the Infinity Stones, it was also mentioned you must have a powerful mind and body to harness such power. When talking about his weapon which became Stormbreaker, Thor told the Guardians that “your bodies would crumble as your minds collapsed into madness” in response to Star-Lord asking why they all can’t receive Thanos-killing weapons.
In Avengers: Endgame, the Avengers have been shown in trailers and described in footage as launching an assault on Thanos. Whether this goes good or bad is unknown, but it will be the first time we see Captain Marvel in action with Earth’s Mightiest Heroes. From the TV Spots and trailers we’ve seen, it appears The Avengers want to undo the Decimation aka the snap thus they’d need to use the Infinity Gauntlet.
In that situation, they’d confront the obstacle of a “powerful enough” character wielding the Infinity Stones. Based on the characters remaining on the Avengers team, the most likely would be Thor, Captain Marvel, Hulk, & Iron Man.
With Thor, he’s been shown time and time again is capable of withstanding severe amounts of damage. In Thor: The Dark World, he directly faced the power of the Reality Stone while in Avengers: Infinity War, he withstood the energy of a dying star forge. It has also been teased in previous films that Odin himself had an Infinity Gauntlet, which arguably was the influence for why Thanos had Eitri created his version.
If Odin could theoretically utilize an Infinity Gauntlet, it would make sense that Thor would also be able to. Thor, thanks to Mjolnir and Stormbreaker, also has experience with powerful weapons made of Uru metal harnessing great power. In an unexpected way, it makes the most sense and wouldn’t be unbelievable based on what we’ve seen from the character of Thor.
The next likely character to use the Infinity Gauntlet would be Captain Marvel. This stems from the fact that her powers come from the Space Stone to the point she radiates the same energy signature. With her abilities, it makes her an easy candidate for wielding the Infinity Stones without drawbacks. This would be important as Thanos upon completing the Infinity Gauntlet experienced brief strain and pain as the power flowed throughout his body.
Her abilities would allow her to properly absorb and not be overwhelmed by the vast amounts of energy. If anything, she’d be put into an elevated version of her Binary form for the duration she used the Infinity Gauntlet. While this would be interesting to see with Carol, nothing has built towards her having the culminative moment vs other characters, but it could explain why she’s been called a “major player” of the film by the Russo Brothers.
The next member of The Avengers I would consider capable of wielding the Infinity Gauntlet would be The Hulk. This resides with how durable his body is and his regenerative abilities. Besides these qualities and a body type similar to Thanos, I think the Hulk would be overwhelmed by the energy of the Infinity Gauntlet. Instead, the science bro that would most effectively use the Infinity Gauntlet would be Tony Stark. With the various armors he has built along with the arc reactor’s energy output, he would be used to working with a high energy source.
Tony would likely need to create a special armor to compensate for the extreme levels of energy the Infinity Gauntlet possesses but it should be possible. Vision’s blank body in Wakanda can serve as a foundation for the technology as his body could harness and utilize Infinity Stone energy without falling apart. Tony Stark being the one to undo the snap or wear the Infinity Gauntlet against Thanos would be the most fitting thematically. It would be a fitting way to sacrifice the character while further mirroring him to Thanos.