Revealing: When the Bodyguard attacks the rival gang, he stabs one of the torch carriers, to which we get a close-up of. As the blade goes in, blood comes out - when the Bodyguard removes his blade, there is no stab wound, not even in the torch carriers clothes.

Revealing: At his first attack, the sword of the bad samurai is a computer generated image. You can see it, because it is waggling unnaturally although the samurai holds it still.