[Good. He's navigated behind him, and whoever this is has lost his composure. Now's the time. Thankfully, one of the things Batman is trained in is ventriloquism... so Leonardo will hear the voice coming from all around rather than just one place. Have Batman's trademark no-nonsense voice.]

Who are you hunting, ninja?

[He says the word "ninja" with an inflection to suggest he's familar with them.]