How Did I Become an Immortal After Guarding the Abandoned Alchemy Room for Four Years?

Li Xian's life took an unexpected turn when he transmigrated into the body of a dying old servant in a sect. He initially intended to die peacefully in the sect, but ended up making a deal with his beautiful junior niece. In exchange for her time in the abandoned alchemy room, he would cultivate with her. However, this cultivation awakened the Yin-Yang Xuanhuang Cauldron, granting him not only the ability to collect Yin-Yang energy from cultivation but also the power to transform waste into treasure. From then on, the abandoned alchemy room, which everyone avoided, became Li Xian's paradise. Thanks to his ability to turn waste into treasure, countless female disciples of the sect threw themselves at him. Li Xian: "Holy Maiden, you wouldn't want to feed this top-grade Divine Transformation Pill to a dog, would you?"