She Dao 

In troubled times, the bladesmiths would emerge, and they would offer a suitable blade to those destined to wield it. No payment is required, but the bladesmith will leave a cryptic prophesy behind. Only when the prophecy is fulfilled will the smith return to collect the "blade price." Shu Yu, a boy born into the lowest caste, meets the bladesmith Tang Dao and receives the sword named "Muzheng." He was told his prophecy and gained extraordinary power. From that moment, his life will never be the same…