After their village is razed by the tyrannical Taibai Empire, sisters Yin and Ning embark on a nomadic journey. Their childhood companion, Zhao, enslaved by the Empire, employs his ingenuity to navigate his servitude. A chance encounter leads Yin to a legendary sword, bestowing upon her extraordinary combat prowess and the companionship of Yun, a mystical fox spirit. Meanwhile, Zhao befriends a enigmatic girl harboring immense power within the Empire. As the trio becomes entangled in the Empire's power struggle, they must rely on the burgeoning rebel forces' magic and strength to tip the scales of war.