Master AN art! Master a skill! What the fuck are you? Become an intellect, the art of observing, it's not an art, it's manipulatively, what is your motive? Master something. Manipulation is not an art.
Others have commented the assassin is a time traveller. Time travel has nothing to do with it! Affect an unrelated thing in such a way that the knock on effect leads to the death of the intended victim.