'Avengers: Infinity War' has one of the biggest cast in cinematic history, but it appears that it's follow up, the currently untitled 'Avengers 4' is looking to challenge that. The Ancient One, from 'Doctor Strange' is confirmed to appear.
Michael Grillo, executive producer for 'Avengers 4' has confirmed that Tilda Swinton will indeed return to the role. There are a lot of speculations around the plot for the highly anticipated upcoming Avengers film, from having a 5-year time jump, to time-travel. This news gives more evidence of the time-travel theory. However, she being the Ancient One means that it's hard to tell, given that we don't know all of her powers and that this could be just one of them that was never discussed in the 2016 film, starring Benedict Cumberbatch.
This reveal came from the Austin Film Festival, where Avengers 4 screenwriters Christopher Markus and Stephen McFeely along with Michael Grillo were in a panel. SuperBroMovies reports that they discussed the logistical nightmare of scheduling filming 'Avengers 4' does to the star studded cast. A-list actors usually have very busy schedules. Grillo gave an example using Tidla Swinton: "When we got Tilda Swinton, she was just a 1-day availability." It is very likely an accidental slip, but this news is very exciting for us.
'Avengers 4' hits theaters on May 3, 2019.