In a mystical realm infused with Eastern elements, a duo of sacred guardians, a brother and sister, find themselves targeted by the Xuan Gui Zong, minions of the sinister Miè Tian Hai who covets their possession, the Tian Xing Jiàn sword. Despite the brother's fall in the face of Hai's power, the sister, Dan Fei, chooses a daring escape by leaping off a cliff. Meanwhile, a lone swordsman chances upon a desolate temple where a Buddha statue stands protected by a rain-repelling umbrella. When the swordsman claims the umbrella, a passerby warns him of a condition: to show kindness to the next stranger he encounters. Fate intertwines as Dan Fei, chased by the Xuan Gui Zong, becomes that very stranger. Bound by his oath and ensnared by the enemy's dark magic, the swordsman finds himself irrevocably entangled in their dangerous plight.