A red sword? Got it! It's the Undead Slash!

Ashina, the land of reeds, half-kneeling on the ground, looking at the unconscious Jiulang in front of him. ...... "Please live as a human being." Swinging the immortal sword "Bai Lei" on his neck, the blood that should have splashed out turned into flying cherry blossoms floating on the reeds. ——————In the alley of a remote town in the Taisho period, a lifeless body was shining with pink divine light. "Resurrection" The lifeless thin figure sat up in the rain. "Where is this..." So far, the son of God and his ninja wolf, although in two different worlds, are both reborn at this moment! ...