My dream villain list for movies
Superman/Batman: Luthor (you don't want to fill up this movie with too many things) Maybe Killer Frost or the Shade as filler, moderate-level threats for Batman or Superman.
Man of Steel 2: Brainiac
Man of Steel 3: Mongul... or PARASITE (Seriously, why is he not on the list?)
Justice League 1: Darkseid
Justice League 2: Starro