Azafuse cursed demon eaten by beast spear
"who wields the spear shall be eaten by spear and turn into demon"
Beast Spear It was created over 2000 years before the start of the story by Giryou, the son of a master blade-maker, after his sister Jie Mei sacrificed herself to make the spear's blade. Driven mad by his sister's sacrifice, Giryou crafted the Beast Spear, pouring all of his hatred and desire for revenge against Hakumen no Mono, the Youkai responsible for the death of his parents, and by indirect extent, his sister. His very body became the spear's shaft.
first wielder and eventually it transformed him into the first Azafuse