A low-level treasure-seeking spirit mouse accidentally swallows the Myriad Poison Relic, awakens the Xumi Universe Realm, and can swallow all things to turn them into cultivation. It battles the Withered Bone Old Demon with wits, loots the Xuanmu Sect's spiritual medicine garden, swallows the Myriad Beast Pavilion's treasury, and even subdues the Primordial Heaven-Swallowing Beast as a son. One person and one mouse sweep across the cultivation world, gnawing on spiritual veins, swallowing immortal elixirs, and moving dragon palaces, counterattacking from a useless mouse into the heaven-swallowing overlord that makes the entire sect tremble in fear.