The world has finally seen just how the heroes managed to defeat Thanos in Avengers: Endgame but we still have no clue exactly what it was that Doctor Strange saw in the future. After all, the Sorcerer Supreme didn't actually confirm with Tony Stark if that was the future he saw in Avengers: Infinity War. Luckily, the writers behind the two Marvel Cinematic Universe flicks have finally revealed just what happened in that one future where the Avengers won.
Christopher Markus and Stephen McFeely are the writers behind Infinity War and Endgame so they certainly are the best people to reveal what Stephen Strange saw in his vision. Markus and McFeely recently discussed fan theories with The Hollywood Reporter and somehow shared what happened in the one future where the Avengers won.
"The only way this works is if Tony dies. If you go back and watch Infinity War, when [Strange] says 'one,' Benedict … is just choked on emotion. Now that you know the end, go back and watch that moment. He means, 'You're going to have to die, Tony.'"
This should explain why Strange refused to let Thanos kill Tony before every Infinity Stone was collected. If Tony had died in Infinity War, this would mean all would be lost. Unfortunately, it meant that Strange had to give up the Time Stone and give Tony a fighting chance.
It may have been depressing to lose Tony in Endgame but his sacrifice certainly ensured that the universe was saved so it's something that fans have grudgingly accepted. After all, he was destined to do it and we wouldn't have it any other way.
Avengers: Endgame is still screening in theaters worldwide.
Related: How Avengers: Endgame Gave Hulk A Happy Ending After His Long-Time Crisis