Ninja Strike 6 (Whenever one of your opponent's creatures attacks or blocks, if you have 6 or more cards in your mana zone and you haven't used a Ninja Strike ability this attack, you may summon this Shinobi without cost. At the end of the turn you used this ability put this Shinobi on the bottom of your deck.)
Destroy 1 of your opponent's creatures with 4000 power or less.