Rebecca Romijn, 52, will officially return as Mystique. She starred as the shapeshifter in “X-Men, X2: X-Men United,” “X-Men: The Last Stand” and “X-Men: First Class and Joan in The Punisher.”

Robert Downey Jr. returns to the MCU with other confirmed actors including stars Chris Hemsworth and Tom Hiddleston, 'X-Men' stars like Patrick Stewart and Ian McKellen, and a good chunk from the studio's 'Thunderbolts.

The livestream revealed 27 actors from across Marvel’s history starting with the first X-Men movie in 2000 to the most recent phase five Marvel movies and shows. Perhaps the most surprising of the names were cast of Bryan Singer’s X-Men and X2 including Patrick Stewart, Ian McKellan James Marsden, and Alan Cumming.