When the limit is reached, there's no more art. And yet, martial arts still isn't magic. The mysterious things always break down to something simple and logical, like basic techniques, speed or endurance. If I make a clever move against a student in class, I don't try to mystify it by saying it's a secret move. Besides, if the student doesn't train correctly, he won't be able to use the move.
Mastery depends on training.
There has never been a martial arts master who hasn't thoroughly trained. This is the genuine way of true martial arts.