Throughout the course of the Marvel Cinematic Universe, there have been three Infinity Gauntlets: the one in Odin’s vault, the one worn by Thanos in the post-credits scene of Avengers: Age of Ultron and the one in Avengers: Infinity War that Thanos forced Eitri to forge.
While the existence of three completely different gauntlets has led many fans to come up with crazy theories about h they came to be, the writers of Infinity War actually have a pretty decent answer to the conundrum.
The Infinity Gauntlet made its debut appearance in the first Thor film in 2011 as one of Odin’s many prized possessions in his vault — which was later revealed to be a fake by Hela in Thor: Ragnarok. The second Gauntlet was seen a few years later during the post-credits scene of 2015’s Avengers: Age of Ultron, where Thanos was shown to be already wielding the gauntlet several years before the events of Infinity War were set to begin. Several fan theories came out regarding why there were multiple gauntlets, including one in which the fake gauntlet serves as a reminder to Odin of his past as a conqueror. Another theory suggests that the post-credits scene from Age of Ultron is out of sequence, and could very well have taken place right before Infinity War.
This creates a bit of a problem, as Infinity War suggests that the functional Infinity Gauntlet used in that movie was constructed much more recently on Nidavellir, and most likely to be right after the events of Thor: Ragnarok, as the Asgardians never came to defend the Dwarves that created the weapons. SO, if that was the real Infinity Gauntlet, then what was the one that Thanos was using a few years ago around the time of Age Of Ultron? Well, Christopher Markus and Stephen McFeely, have finally solved the puzzle.
During an Infinity War watch party with live commentary from Markus and McFeely, the duo was asked about the previous appearances of the Infinity Gauntlet in the MCU, to which they replied in a tweet saying “I believe there is an existing myth of a gauntlet that could unify the stones. Hence the fake one in Odin’s vault, and Thanos wearing this fashionable “practice gauntlet.” When he needed a real one, he went to Eitri. Who also provided a handy carrying case.”
When Thor, Groot and Rocket went to Nidavellir during Infinity War, they noticed a discarded gauntlet lying at the forging facility, which could very well be Thano’s “practice gauntlet” that he was using since Age of Ultron. Thor knew immediately what had happened just by seeing the gauntlet, as he knows of its capabilities since another version of the gauntlet was in his father’s vault since before he was born (this was implied as Hela recognizes it as a fake despite being trapped in Hel before Thor’s birth). It was likely that Thanos only stopped using his “practice gauntlet” after the events of Ragnarok, as the forces of Asgard were no longer there to defend the Dwarves.
So, the gauntlet shown in Age of Ultron was nothing more than a gauntlet used by Thanos to practice wielding the Infinity Stones and was discarded immediately the moment he needed the real one. The explanation about the multiple gauntlets from Markus and McFeely puts to bed the often confusing question of when in the prime MCU timeline did Thanos retrieve the Infinity Gauntlet. However, this also makes one wonder why there was not one, but two fake gauntlets created and which one of them came first. Well, with the Infinity Stones and the Gauntlet out of the way now in the main MCU timeline post-Endgame, it’s unlikely we’ll get the answers to those questions anytime soon.
The reason three Infinity Gauntlets have appeared in the MCU was finally explained by Infinity War writers Christopher Markus and Stephen McFeely.