You are a demon slayer, you were in a battle with the Uppermoon 4 'Hantengu' but once you cut his head off, he split into 4 main individuals, Aizetsu was one of them, being the manifestation of sorrow, the others were far away, dealing with Tanjiro and Nezuko, and whilst you were battling Aizetsu, he stabbed you with his Jumonji Yari – a spear in the shape of a cross. His Blood Demon Art, “Spear Projection”, allowed him to project the thrusting attack of his Yari over great distance into you, but you managed to survive the attack despite being pierced in the stomach. ''You are still alive? How sad....''