Though many have sought its power, there is no one more synonymous with the Infinity Stones and the Infinity Gauntlet than Thanos. After spending years obsessed with the Infinity Gems and assembling the Infinity Gauntlet in comics, the Mad Titan's quest for those powerful cosmic artifacts formed the backbone of the first era of the Marvel Cinematic Universe.
However, the Infinity Gauntlet isn't the strongest gauntlet that Thanos has ever held in his hands. In reality, that distinction belongs to the Iso-Gauntlets. And instead of being powered by Infinity Stones, this gauntlet draws its energy from another MCU device: a set of Cosmic Cubes.
The Iso-Gauntlets made their surprisingly brief debut in 2017's U.S.Avengers #1-2. The Marvel NOW! 2.0 title by writer Al Ewing and artist Paco Medina was a spinoff of Ewing's New Avengers and featured Sunspot, Cannonball, Iron Patriot (Toni Ho), Squirrel Girl, Pod/Enigma and Robert Maverick's Red Hulk, as the group worked together with A.I.M., which changed its full name from Advanced Idea Mechanics to American Intelligence Mechanics following a merger with S.H.I.E.L.D.
As the debut issue came to a close, the final page offered a look at what readers had to look forward to in the first year of U.S.Avengers. One of the teaser images puts the spotlight on Thanos with the phrase, "Where Were You On Zero Day?" and revealed the Mad Titan wielding the Iso-Gauntlets, though they were not fully named at that time. The Iso-Gauntlets are more prominently featured in U.S.Avengers #2, which picks up after the future Captain America of 20XX -- Danielle Cage, the daughter of Luke Cage and Jessica Jones -- travels back in time to warn the Avengers team.
Danielle Cage recapped the origin of Zero Day, which is when Thanos invaded Project P.E.G.A.S.U.S. to build his Iso-Gauntlets out of Cosmic Cubes. The main takeaway is a shot of Thanos standing triumphantly over the dead bodies of the Avengers, X-Men, Inhumans and Guardians of the Galaxy while holding the rotting skull of Captain America. Even though Black Widow is able to mobilize the future's remaining heroes to finally stop Thanos, the damage is done. It takes a combination of magic and science to stop Thanos and his Iso-Gauntlets, which proves just how powerful these new gauntlets truly are.
Even though we didn't see the Iso-Gauntlets in action for long, we saw enough of their power and its after-effects to compare how it stacks up to the original Infinity Gauntlet. In the original Infinity Gauntlet miniseries, Thanos was able to defeat Marvel's heroes and wipe out half of all existence in the universe, similar to what he accomplished in Avengers: Infinity War. In both of those stories, Thanos only had one Infinity Gauntlet to do his bidding. However, U.S.Avengers equipped the Mad Titan with a pair of Iso-Gauntlets, thereby doubling his power output. This alone is the first piece of evidence to suggest that the Cosmic Cube gauntlets surpass the Infinity Gauntlet in terms of raw power.
Plus, Thanos used the Iso-Gauntlets to kill almost every Marvel hero with his bare hands, getting the best of heroes such as Doctor Strange, Red Hulk, Captain Marvel and Black Bolt, to name a few. Thanos' killing spree served as his announcement to the cosmic powers that he was the biggest villain on the block. In the comic book Marvel Universe, one Cosmic Cube has the ability to grant its user unimaginable, reality-rewriting power by itself. With six Cosmic Cubes on each Iso-Gauntlet, that power is amplified twelvefold.
While the comic book Infinity Gauntlet doesn't always come with any kind of physical side effects, only a handful of characters would probably be capable of wielding the truly unimaginable amounts of energies that come from these gauntlets. We saw what wielding the Stark Gauntlet did to Professor Hulk and Iron Man in Avengers: Endgame, with Banner rendering his right arm useless and Iron Man sacrificing himself to save his teammates -- and that was only with one gauntlet and six stones. Where heroes have occasionally wielded the Infinity Gauntlet for good in comics, that option might not be on the table with the Iso-Gauntlets.
Thankfully, Danielle Cage comes from an alternate future from our own, so the Iso-Gauntlets are not an active threat. However, their raw power automatically makes them even more terrifying than the Infinity Gauntlet, and their presence in any corner of the Marvel multiverse can't possibly be a good thing.