A lot of people have pointed out the similarities between the plots of Iron Man and Doctor Strange, both of which feature a lead character with a goatee who we first meet as brilliant but arrogant individuals working at the top of their respective fields. Both then suffer major injuries before slowly but surely become less selfish as they grapple with newfound power and responsibilities.
Based on their shared origin stories, it didn’t come as a surprise that there was plenty of bickering banter between Benedict Cumberbatch and Robert Downey Jr. when they first crossed paths in Avengers: Infinity War, because the two superheroes have a lot more in common than either would be willing to admit, and that connection will only be reinforced when the Sorcerer Supreme shows up in Spider-Man 3 to act as Peter Parker’s latest mentor.
During Avengers: Endgame‘s climax, it was Doctor Strange who nudged Tony in the direction of making the ultimate sacrifice play to save the universe by reminding him that there was only one reality where Earth’s Mightiest Heroes would be able to succeed against the threat of Thanos, and Scott Derrickson has now revealed in a social media post that the moment was completely improvised, as you can see below.
Benedict told me this moment was an improv. https://t.co/d5fvwTTrwl
— N O S ⋊ Ɔ I ᴚ ᴚ Ǝ ᗡ ⊥ ⊥ O Ɔ S (@scottderrickson) October 27, 2020
As far as improv on a major blockbuster goes, extending your index finger is hardly going to have the writers scrambling to adapt the script, although it does raise the question of how Doctor Strange was originally supposed to signal that this was their one and only shot at redemption when the moment in Avengers: Endgame is a subtle callback to Infinity War that saw Tony realize what he had to do.