She Dao

During a time of instability, bladesmiths appear and provide a fitting weapon to those fated to use it, without asking for payment. They leave behind an enigmatic prophecy, and only after it is fulfilled will they return to claim the "blade price." A young man from the lowest social class encounters the bladesmith Tang Dao and is given a sword called "Muzheng." He is told his prophecy and granted remarkable strength. His life changes irrevocably from that point.