Ninja Strike 4 (Whenever one of your opponent's creatures attacks or blocks, if you have 4 or more cards in your mana zone and you haven't used a Ninja Strikeability 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.)
When you put this creature into the battle zone, your opponent must choose 1 card from their hand and discard it.