Sword of Shennong.

After war with demons The Great Shennong, Divine Farmer and Father of the Gods, used hell furnace to create mysterious jade sword. With help of this blade he sealed the demon king in Purgatory Well and passed the three artifacts to the Moyue tribe, the Xuanwu tribe, and the Xiuxianyuan respectively. Thousands of years later, the god king fell, and the Xuanwu clan launched a war to seize the artifacts for greater strength, regardless of the ancestral training.