Avengers Doomsday trailer: The MCU, X-Men and Avengers join forces for a face-off with Robert Downey Jr's Doctor Doom

Avengers Doomsday trailer was released.

Robert Downey Jr appears as Doctor Doom.

Trailer features X-Men, Fantastic Four, Avengers, and Thunderbolts.

Story involves a face-off between these groups and Doctor Doom.