Physical attack doing +4 power stages of damage. If you declared a Tokui-Waza and your opponent has a Sensei Deck, you may place your opponent's Non-Combat or Ally cards in play into his Sensei Deck one at a time until he either has no more Non-Combat and Ally cards in play or until his Sensei Deck has reached its maximum size (whichever happens first).
And yet, you showed mercy to everyone, even your fiercest enermies. Even me.