Tōshū

Toshu is swordsmith who was supposedly forced by Ryujin, a humanoid dragon wanted him to forge Datsuki. To remind him of the deal, he gave Toshu a mark on the right eye. Fearing for his own life, Toshu attempted to forge Datsuki, with many failed attempts. Inuyasha and his group protected him and defended him when Ryujin came for the sword. When Ryujin was defeated, he plunged Datsuki into Ryujin, allow it to consume his youki and become a youkai sword. It was then revealed he was the one who offered to forge a sword for Ryujin. He met his demise when Datsuki, afraid of breaking, instead let Toshu's entire body take the damage, thus killing him.