I’m a Sword Immortal in a Western Fantasy World

Sean transmigrated to a Western fantasy world, but received a cultivation System. From then on, the world had an immortal. While others cultivated battle auras to become professional fighters, he cultivated immortality. While others practiced magic to become mages, he cultivated immortality. Ding! You have received the System for Becoming an Immortal and Ancestor. Newcomer mission: Slay this demon chicken, which has reincarnated three times. Every one of its feathers is a priceless treasure, capable of transforming into underworld flames that can burn the heavens and destroy the world. But right now, it has reincarnated to undergo a tribulation and lost its mind. Its demonic feathers are dim, and its evil flames are gone. This is its weakest moment. Please slay it. Reward: Immortal-grade cultivation manual, Eternal Sword Codex. Sean stared at the utterly ordinary hen being held in someone’s hands and fell silent.