Let's recreate the Arkham Origins scenario for Superman--with Lex Luthor as Black Mask. Who do you choose to fight the Man of Steel in a video game?
(Yes, Arkham Origins only has 8 Assassins, but Superman is tough, so we can give him one more guy. =])
1. Atomic Skull (the serial killer version from the New 52)
5. Manchester Black
9. Silver Banshee