10) Mercy Graves
Not that you would know it from how seriously short-changed the character is in the film, but Lex Luthor’s assistant in BvS is Mercy Graves, a pre-existing character in Superman lore.
Graves was first featured on Superman: The Animated Series, in which she was Luthor’s chauffeur/kickass bodyguard. Despite casting Tao Okamoto – who proved herself a dab hand at action scenes in The Wolverine – this version of Mercy sadly didn’t get to show off her fighting skills before she was unceremoniously blown up with the rest of those at Superman’s trial halfway through the film.
It’s also worth a mention that this trial, plus the lengthy discussion of Superman’s existence and methods, is drawn from a classic comic from 1972. In that story, however, it isn’t the US government that puts Superman on trial but the Guardians of the Universe, who believe that the Man of Steel is a negative force.