The Art of the Piercing Void (暗極重波弾の術, Angyoku Juuhadan no Jutsu; "Art of Extremely-Heavy Dark Bullet Wave") is a Ninpo Art used by Ryu Hayabusa in Ninja Gaiden: Dragon Sword and Ninja Gaiden II. It can be found at the beginning of chapter 10 in Ninja Gaiden Dragon Sword. In Ninja Gaiden II it is found during chapter 7, in a chest opposite the Test of Valor. If not found it may be purchased later on.