The "Doomsday" plot leak also seems to confirm the big fight at the X-Men mansion in the universe where Monica Rambeau ended up at the end of "The Marvels." That universe's anchor being is a Professor X (Patrick Stewart) variant that Doom wants to kill. Interestingly, Earth-616 and Earth-10005 -- where Monica is -- are on a collision course.

First Steps" has a thrilling ending that teases Dr. Doom and where the MCU goes from here in "Avengers: Doomsday."

First Steps, the Russo brothers have teased its connection to their much-awaited MCU movie, Avengers: Doomsday. The directing duo recently took to social media to share a promotional post for the first entry in Phase Six of the MCU,