"Close your eyes and accept death."
Hiraishin Kaizai Satsu (Lightning Rod Intervention Murder) is the most powerful of the Hidden Denkouken Arts.
User internalizes his own ki, supplanting the normal neurochemical and action potential functions of his cells, and increasing their speed and efficiency two fold. This creates a magnetic pulse that when focused as a directed strike to the chest, would result in instant ventricular fibrillation though user can target other organs  as well. It is said that this technique is strong enough to kill an elephant in one blow. Ayabe's "instant kill" technique that turns the human heart (or any other organ in the target) into a crackling piece of meat. In a bit of an inversion, Ayabe was legendary among his school of martial arts not for mastering this killing technique, but for being so good at it that he could use it non-lethally, giving someone a heart attack but not killing them.