Demon Sword Nihil (妖刀似蛭) is fictional sword in Osamu Tezuka's manga series, Dororo. Nihil is one of the 48 demons that devoured the protagonist Hyakkimaru's flesh when he was an infant. It's a living demonic sword that possesses its user, causing the user to turn into a berserk warrior, to sate its bloodthirst.
A Nihil blade can be acquired in Ueno. By walking counter-clockwise around the statue near the center of town, the hero gets transported to a small, isolated island the Expanse where the Nihil is thrust into the ground. In Kyūyaku, by returning here again after speaking with Lucifer, the Hinokagutsuchi will be found.