Kaiu Bakin was a weaponsmith of the Crab Clan. He was the owner of Kuro Suchiro at Otosan Uchi. In 1123 he crafted strong weapons and armor with the ore found in the Oni Warai. He was not aware the deposits had been corrupted by the presence of an oni trapped beneath, and Bakin suffered the effects of the taint. He gained inhuman strength and endurance, but Bakin believed his creations were alive, and began to speak with them.