He once wield the Shibien, one of Muramasa's Devil Swords and killed too many people with it until it's turned the sword color into black because the sword absorbed too much blood.
He once wield the Shibien. He once killed too many people with it. It's turned the sword color into black because the sword blood. This sword is absorbed too much. The Shibien is one of Muramasa's Devil Swords.