A new Avengers: Endgame theory explains exactly why only Tony Stark’s Iron Man was capable of defeating Thanos and his armies during the Battle of Earth. Bringing the MCU Infinity Saga to a close, Avengers: Endgame detailed Earth’s Mightiest Heroes’ last stand against Josh Brolin’s Mad Titan, Thanos, after he snapped away half the population of the universe five years earlier. Robert Downey Jr’s Iron Man was pivotal to this mission, as his discovery of time travel allowed the Avengers to embark on the Time Heist to collect the six Infinity Stones.

However, the Avengers’ Time Heist also allowed a version of Thanos from 2014 to travel through the MCU timeline to the present day, culminating in an epic battle between Thanos and the Avengers, joined by their returned allies. The Avengers put up a good fight against Thanos and his army, but only one man could truly save the day. Robert Downey Jr’s Tony Stark had been the face of the MCU for over a decade, so it was only right that he was given the opportunity to defeat Thanos once-and-for-all, though this came at the cost of his own life.

Iron Man Defeated Thanos Thanks To His Armor In Avengers: Endgame

Iron Man’s Armor May Have Given Him Enough Protection To Survive The Infinity Stones’ Power For Long Enough

Ever since Iron Man snapped his fingers and defeated Thanos in Avengers: Endgame, many have questioned whether any of the other Avengers could have taken his place, and perhaps survived. A new theory posed by Voyant suggests that this wouldn’t have been possible, and gives strong evidence suggesting Iron Man was the only hero capable of enacting this feat. The theory posits that Iron Man’s armor made it possible for him to briefly withstand the immense energy of the collective Infinity Stones, especially since Tony Stark’s Avengers: Endgame suit wasn’t just any old Iron Man armor.

The version of Iron Man’s armor used in Avengers: Endgame was Mark LXXXV (85), which was created using nanotechnology for a sleeker design than his previous suits.

Iron Man’s suit of armor in Avengers: Endgame was seemingly designed with the ability to hold and absorb the power of the Infinity Stones. The Stones slotted perfectly into pre-designated grooves on Tony Stark’s hand, while the energy from the Infinity Stones was evenly distributed throughout the suit, allowing Tony Stark to stay alive long enough to perform the snap that saved the universe. This could explain exactly why Stark was the only hero capable of defeating Thanos in Avengers: Endgame, and suggests that any other hero would have suffered even graver consequences than the armored Avenger.

Why The Other Avengers Couldn’t Have Done The Snap

Heroes Including The Hulk, Thor & Captain Marvel May Have Been Able To Survive The Snap

Earlier on in Avengers: Endgame, the Avengers themselves squabbled over who would have the responsibility of using the Infinity Stones to reverse the damage caused by Thanos five years earlier. Bruce Banner’s Hulk deemed himself the only hero capable of withstanding the Infinity Stones’ energy, given the fact that the Stones emit gamma radiation, and his own body is infused with immense levels of gamma. However, other heroes did put themselves forward, most notably Thor, who questioned whether the lightning running through his veins would allow him to wield the Infinity Stones safely.

Thor went through serious mental struggles in Endgame, however, suggesting his will may not have been robust enough to use the Stones against Thanos. Others, including Captain America and Hawkeye, had no protection, so would have felt the full force of the Infinity Stones’ energy. Spider-Man did have a Stark-designed costume, but it’s unlikely the other Avengers would have allowed someone so young to wield the Infinity Stones. Captain Marvel perhaps could have used the Stones, but she had already been taken out of commission by Thanos using the Power Stone, leaving Iron Man as the only possible candidate.

How The MCU Would Be Different If Iron Man Didn’t Snap & Survived Endgame

Iron Man’s Survival In Avengers: Endgame Would Have Seriously Changed The MCU’s Multiverse Saga

If someone else, such as Captain Marvel or Thor, had used the Infinity Stones against Thanos during the Battle of Earth, Iron Man could have walked away from the battle unharmed. This would have had huge implications for the MCU’s future, as Tony Stark’s demise has played a major role in several Multiverse Saga projects, and is only set to become even more prevalent. Most notably, Rhodey’s Phase 4 and 5 storyline has been building up to his upcoming appearance in the cast of Armor Wars, a pseudo-Iron Man 4, which will deal heavily with Rhodey’s actions following Stark’s death.

Had Tony Stark survived the events of Avengers: Endgame, he could have returned to his wife and daughter, and continued his career as Iron Man. However, this may have seen another powerful hero sacrifice their life in his place, which may have made the development of projects such as Thor: Love and Thunder and The Marvels impossible. Tony Stark’s death has empowered other heroes to continue his legacy, though Robert Downey Jr. has recently teased his return as the armored Avenger. Even so, Marvel Studios remains quiet on whether the Academy Award-winning actor will reprise his role.