Father's Old Enemy: Ryukotsusei.Hop­ing to find a way to wield the Tetsusaiga, In­uYasha goes to To­to­sai, who instructs him to slay Ryukotsusei, a dragon daiyōkai who was sealed into a dormant sleep with one of the claws of InuYasha's father, Inu no Taisho. Achieving this task will therefore gain InuYasha the strength required to lift his reforged sword. This backfires when Naraku comes to awaken the dragon. InuYasha is unable to fight as Ryukotsusei repeatedly attacks with the Thunder Attack Bullet, the pure white energy spheres that are launched out of his mouth.