Avengers: Doomsday - Character Breakdown
8. Professor X
How do you follow a name like Tom Hiddleston on an Avengers cast reveal? How about with Patrick Stewart? Like Loki, Professor X has died multiple times on screen, see X-Men: The Last Stand, Logan, and Doctor Strange in the Multiverse of Madness, and also like Loki, his appearance in Doomsday is more than welcome.
Along with Beast, Charles Xavier is one of the only X-Men to have appeared in the MCU so far, though his time didn't last long. He was Earth-838's Professor X, who was a part of the Illuminati and was quickly killed by Wanda Maximoff (Elizabeth Olsen). This won't be the same version of the character, but there is no real telling right now which version it will be.
There are big gaps in Fox's X-Men story, with the entire timeline being wiped out in Days of Future Past, then nothing between Dark Phoenix in 1992 and when Wolverine returned from the past, and only spotty accounts of what happened between then and the events of Logan.
This is more than likely to be yet another new version of the character, and one that hopefully will not die this time.