Robert Downey Jr. cried when he first heard about Iron Man's Avengers: Endgame story. As the actor who helped launch the Marvel Cinematic Universe back in 2008, Downey has always been one of the biggest parts of Marvel's plans. This was especially true as Kevin Feige and the team at Marvel Studios began figuring out what would happen when the Avengers and Thanos finally fought in Avengers: Infinity War and Avengers: Endgame. All of the MCU's main characters were featured in the climactic films, but Iron Man's story received an even bigger spotlight based on the plans for him to die.

After Thanos snapped away half of all life across the universe in Avengers: Infinity War, Tony Stark's story in Avengers: Endgame took some surprising turns. He gave up being a superhero once he returned to Earth and spent time starting a family with Pepper Potts, which included raising their daughter Morgan. However, Stark couldn't stay out of the game forever and had to tinker with ideas of how time travel through the Quantum Realm would work. The Avengers' plot to retrieve the Infinity Stones in the past allowed Tony to reconnect with his father and ultimately make the biggest sacrifice possible. Iron Man used the Infinity Gauntlet and Stones to save the universe, even though it meant his death.

Related: Endgame Almost Killed All 6 Original Avengers

Iron Man's death in Avengers: Endgame, the holographic message he left, and his funeral gave the movie a chance to end in an incredibly emotional way for fans. Most had spent 11 years watching Tony Stark grow to become one of the MCU's greatest heroes. As emotional of an experience as it was for viewers, the conclusion to Iron Man's story was even more emotional for Robert Downey Jr. As part of Marvel's behind-the-scenes book The Story of Marvel Studios: The Making of the Marvel Cinematic Universe, it's been revealed that just hearing the direction of Iron Man's Avengers: Endgame story was enough to make Downey cry.

"When the Russos' presentation to Downey Jr. got to Tony Stark's last moments, their nerves began to fade. But their belief in the story was solidified. "When we started winding down the pitch, and getting to his death, Robert started crying," shared Joe Russo. "And when we were done, he said 'That's f--king awesome.' That's when we knew that we had to do it. Because he felt it."

Iron Man snaps his fingers wearing his version of the Infinity Gauntlet in Avengers: Endgame

Downey's emotional reaction to Iron Man's Avengers: Endgame story lines up with how most viewers felt come April 2019. However, he experienced the arc several years before when the Russo brothers first laid out the plan. Iron Man's death wasn't a huge surprise to Downey, as a broad idea of this arc was explained to him before signing on for Captain America: Civil War, but the specific details of what the movie included still hit him. It's a testament to the story the Russos and writers Christopher Markus and Stephen McFeely crafted. He also famously didn't want to return to film the "I am Iron Man" line from the finale in reshoots because of the emotional toll, so this was just the beginning of the moving ending to Iron Man's MCU journey.

The tears from Robert Downey Jr. that Tony Stark's story elicited are also another reminder of how much this role meant to him. It might be easy to look at Downey's fame and money that came from the MCU and presume that that's all he cared about. However, the actor clearly has a strong connection to Iron Man and cared deeply about his story ending in the right way. It's one of the many reasons why fans continue to debate whether or not Downey should ever return. Considering how hard Tony's Avengers: Endgame story hit Robert Downey Jr. emotionally, it's no surprise fans have such strong feelings about what Iron Man's MCU Phase 4 future should be.

More: Marvel Hints How Iron Man Could’ve Survived Endgame

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