Dark Nisshō

Dark Nisshō (闇の日照, yami no nisshō; dark sunlight) is a fragment of Nisshō Asakura's soul, broken off after he was impaled with the during his presumed execution. It was infused with the core of his Hell-based powers and a small fragment of his Shinigami abilities. Following his split from Nisshō, it traversed the Dangai to where it devoured Hollows, to feed its hunger and power.