Civil war
Who do you think he will be playing in the new Captain America??
shareDoctor Strange, and nobody has confirmed he'll be a villain, however he is confirmed to be playing in both Doctor Strange and Cap 3.
Zemo and Red Skull make no sense in Strange, and there's very little overlap at all between the two films except for Strange himself.
Only other option is if they combined characters from the two books, which would put Zemo/Mordo and Surtur/Dormammu on the table. Lol if you don't read comics that prob made no sense but... Yeah