You probably remember Tao Okamoto from Wolverine, where she played Mariko. Did you know that she is also to be in Batman vs Superman: Dawn of Justice? While her involvement in the film is confirmed, it has only been this week that rumors from the set have started to leak suggesting that she will be playing Lex Luthor's assistant, Mercy.
Mercy Graves first appeared in the DC Animated Universe, but was one of a few later adopted by the mainstream comic book universe. If the casting rumors are correct, it makes sense to assume that the Mercy we will be seeing in the movie will follow the animated version of the character, because they are physically similar. (As opposed to the blonde, possibly Amazonian version of Mercy seen in the books.)
The character herself is Lex Luthor's bodyguard and chauffeur, and in the animated series is cold, witty, and an incredibly talented hand-to-hand fighter.
As the second ever movie role for this Japanese model-turned-actress, the question is, how big will the role of Mercy be, and can she handle it?