Fandango: Was there a pairing or partnership that you were most excited to see or a pairing that you think audiences are most excited to see among the Avengers?
Joe Russo: Amongst the Avengers, let me see here. I think Tony Stark and Doctor Strange is a really interesting pairing and a really compelling pairing. It's a bit of an odd couple, and we used to reference DeNiro and Grodin from Midnight Run, so it's a somewhat contentious clash of egos, but very interesting and it has a big impact on the story
Here they are a theory on possible DS role on the movie based on the comics: a double agent!
In Jonathan Hickman's 2013 Infinity event, which is one of the main influences for Infinity War, Doctor Strange had a run-in with Ebony Maw of the Black Order. Maw was sent on a mission by Thanos, tasked with using Doctor Strange to reveal the location of the Infinity Stones. At the time, Strange was one of the few people who actually knew the locations of the powerful stones, so Ebony Maw needed to extract that information.
Unfortunately for the people of Earth, that's exactly what the villain was able to do.
Ebony Maw used his mental abilities to twist and turn Strange's will, causing him to not only reveal information, but become a double agent for Thanos. It's because of Maw's work that Thanos was able to find the remaining Infinity Stones.