The power of the Infinity Gauntlet in the MCU was alluded to way back in Thor when it appeared in Odin's vault. Being that Odin's vault was a museum of all-powerful objects, it had to be important. While comic fans knew the extent of its power, the average movie-goer may not have known what was to come. Though it was revealed later that this was simply a replica of the real deal, the reverence towards the object speaks to its power. The plot thread of Thanos gathering the stones that the gauntlet houses and the efforts he went to in order to retrieve the stones show that it really is the prize he made it out to be.
We were also shown the power of some of the individual stones over the course of the MCU to date. The idea that these stones could be gathered to become something even more powerful is flabbergasting. Unfortunately for 50% of all life, Thanos successfully brought them together and enacted his infamous finger snap. Of course, Thanos is not the only one who has wielded the Infinity Gauntlet. Several heroes and villains throughout Marvel's comic history have lifted the fated hand of Infinity. Let's take a look into the source materials, the comics Thanos resides within when he's not on the silver screen. Once we do, we'll encounter others who proved to be highly dangerous with the gauntlet...
There is a singular instance in which Peter Parker wielded the Infinity Gauntlet, stones and all. It came in the form of a story that ran through a four part miniseries in which Thanos once again sought to cull a large portion of the universe. Thanos lets slip of the gauntlet while fighting a doombot of all things, and Spidey is able to take it.
Parker proceeds to undo all of the damage done by the Mad Titan, which indicates his aptitude for using the gauntlet -- a difficult turn for somer wielders. Luckily, great power did not affect his sense of responsibility as he relinquished the gauntlet and its tempting omnipotence. Sadly, in resolving everything, he inadvertently wipes the memories of his comrades, meaning no one remembers his heroic feat.
In the Ultimate Marvel Universe, there are two Infinity Gauntlets. As if that prospect isn't scary enough, the reason there are two is because there are eight Infinity Stones. With that amount of stones, anyone could be granted amazing power. As he is already incredibly powerful, the last person you'd expect to have a go on the gauntlets is the Hulk.
There's a good reason for this, however, as Hulk had recently escaped imprisonment and wanted to get some revenge on the Ultimates. No matter what they did to the Hulk to stop him, he'd simply undo it with the gauntlets. It wasn't until they melted the big guy and he reformed only wearing one of the gauntlets that he was weakened enough to be stopped.
13 CAPTAIN AMERICA
In the build-up to the multiversal collapse that would culminate in Time Runs Out and Secret Wars, the Illuminati tried several things to prevent the incursion of all worlds. There were several members of the Illuminati who were trusted to safeguard an Infinity Stone each. Bringing the stones together, they decided to try and use the power of the Infinity Gauntlet to remedy the collapse.
The member of the group that was nominated to do so was Steve Rogers, who used the gauntlet to try and reverse an incursion. While he appeared successful, the effort of carrying out the act shattered all of the stones apart from the Time Stone, which simply disappeared.
12 IRON MAN
It may be that you'd think Tony Stark, having access to ultimate power, would be a bad thing. The allure of the power mixed with his sometimes obstructive ego is a potential recipe for disaster. His logical thinking won out, however, as he was able to relieve himself of the power after wielding it for a short time.
If Tony had been given more time with the Infinity Gauntlet, it would have only been a matter of time before he made a suit around it. Stark may have even done away with the gauntlet entirely and made slots for the stones throughout his suit.
11 BLACK PANTHER
Black Panther was entrusted to use the Infinity Gauntlet to stop Doom in Secret Wars. Dr. Strange left the item of power to his fellow Illuminati members to topple God-Doom. Both Namor and T'Challa were present in Strange's vault, though Namor deferred the power to Black Panther, citing he knew they couldn't trust him with the power.
Black Panther used the Infinity Gauntlet and his influence over the undead as Wakanda's King of the Dead to launch an assault on Doom's forces. What followed was a clash between the power of the Beyonders, wielded by Doom and the power of the Infinity Gauntlet, wielded by T'Challa. He even used the stones to create himself a Panther mech.
It had to happen eventually, right? Deadpool getting the Infinity Gauntlet is the result of him stealing it from Thanos. He did this by harnessing the power of the Cosmic Cube to trick Thanos, replacing his gauntlet with a toy replica. Deadpool tried to host a roast for the Marvel Universe, using the gauntlet to gather everyone together.
Deadpool didn't fully understand the concept of a roast and the event turns into a roast upon Deadpool himself. Wade then takes the stage, using the gauntlet to force everyone to laugh at his jokes. He then turns his aggression towards the reader, acknowledging that being a comedic character all the time for readers' amusement annoys him.
9 DR. DOOM
Doom loves to get his hands on power beyond comprehension. The ruler of Latveria has taken the power of the Beyonders on two occasions! So, when given the chance to have a cheeky go of the Infinity Gauntlet, Victor took it. After seemingly perishing in battle, Doom wakes up in the former citadel of the Council of Reeds.
The Council of Reeds being a collection of Mr. Fantastics from all over the multiverse, some of them had acquired Infinity Gauntlets from their respective universes. Doom retrieves two gauntlets from the rubble and raises an army made from multiversal versions of himself, who were lobotomized and held prisoner in the citadel depths.
8 MR. FANTASTIC
Reed Richards has held the Infinity Gauntlet in multiple universes. In 2012, when the main 616 Reed was introduced to the multiversal council of Reeds, a few of them were seen wielding gauntlets. However, the main Reed once tried to destroy the gauntlet's power entirely.
Attempting to use the Infinity Gauntlet to will the Infinity Stones out of existence, to remove the danger they posed, Reed ultimately failed. The power proved too much for the Fantastic Four leader, the internal conflict the gauntlet caused within him rendering him unable to see his goal through. Later, however, all of the stones (apart from the Time stone) would accidentally be destroyed by Steve Rogers.
7 ADAM WARLOCK
Adam Warlock has a unique power set which is aligned with the Soul Stone. He managed to transfer himself into the Soul Stone while the gauntlet was being wielded by Nebula. He used his influence over his stone to reach out to the others and remove the gauntlet from Nebula.
This influence and power over the gauntlet through the stones is something that no other wielder appears to have. Unfortunately for Adam, he would be told to relinquish the power or lose it forever by the Living Tribunal. He dispersed the stones from the gauntlet among his Infinity Watch team for safekeeping.
6 GREEN GOBLIN
In a Dark Reign-inspired "What If?" scenario, Norman Osborn manages to attain the Infinity Gauntlet. Over the course of the story, he shows the sheer power of the gauntlet by easily defeating the Sentry and other heroes with it. One of the worst things he does with the gauntlet is make Spider-Man relive the end of Gwen Stacey over and over.
Throughout the story, Norman is bringing his father along for the ride. The entire arc appears to be Norman trying to be accepted by his father by showing his prowess. Even by using the reality stone to make his father love him after he remained unimpressed, he is not satisfied. In his anger, he wishes his father out of existence then realizes all too late that without his father, he ceases to exist also.
5 SILVER SURFER
Though the Silver Surfer only wielded the power in a "What If?" story, it showed the effects of ultimate power on the former herald of Galactus. Norrin Radd became more and more corrupted by the power over time. Though his goal was admirable, seeking to make the universe a paradise, it became a little twisted.
He become obsessed with his quest, obsessed with making everything perfect. It wasn't until he granted his partner Shalla Bal with similar power that he was able to see how far he'd fallen. She convinced him of his folly, able to illustrate it through her personal link to the Surfer and the power they now shared.
When Thanos initially gained the full power of the Infinity Gauntlet, he did some really disturbing stuff. He reanimated poor Nebula to make her a walking corpse, an existence of pain and strife. He would then go on to end several heroes and eradicate the cosmic entities that tried to stop him abusing the power of the Infinity Stones.
Once he was done, he left his physical form to exist as part of the cosmos itself. This allowed the shambling body of Nebula to retrieve the gauntlet from his abandoned body. She would restore herself and take vengeance on a universe that brought her nothing but pain. She was eventually stopped by Adam Warlock, however.
Adam Warlock once used the power of the gauntlet to purge all of the evil from himself, which manifested as the villain Magus. Observing Magus' misuse of several cosmic cubes and his designs for the Infinity Stones, Eternity uses their power to make the stones incompatible with one another. So, when Magus acquires the gauntlet it is useless.
Later on, Galactus demands Eternity reverse their decisions due to the stone's role in balance in the universe. Magus is now seemingly in possession of a fully potent Infinity Gauntlet and attempts to set his nefarious schemes in motion. The Reality Stone, however, turns out to be a fake swapped over by Thanos and the confusion that ensues allows Magus to be trapped inside the Soul Stone.
2 SANTA CLAUS
Santa Claus is beloved the world over by those who rely on him to make their holiday season merry. Although, when his reindeer turn out to be replaced by Skrulls and he can't deliver his presents, what can the heroes do to save him? Give him the Infinity Gauntlet!
Surely with the gauntlet's power, he can deliver every present with a snap of his fingers? Absolutely not, as Santa proceeds to go mad with the overwhelming power of Infinity. After beating down several heroes, he is only stopped when Namor removes the gauntlet from him. How, you ask? With a snowball -- a very accurate and powerfully-thrown snowball. Happy Holidays to all!
DC's Darkseid once had the fortune of finding himself in possession of the Infinity Gauntlet. During the crossover event between Marvel and DC, part of the quest to save both universes involved finding objects of power. When the Avengers sought out the gauntlet, they found it on Apokolips in the hands of Darkseid.
As you can imagine, that much power in the hands of a tyrant such as Darkseid cannot end well. Thankfully, due to how the gauntlet operates, it needs to be inside its native universe to work. As the DC universe is something completely different to the gauntlet's home reality, the gauntlet and its stones were inert.