"Swallowing Heaven and Devouring Earth: I Am the One Who Ushers in the Dark Age" tells the story of Li Feiyu, who falls into the demonic path after his cultivation partner betrays him. In a desperate predicament, he obtains the heaven-defying "Heaven-Swallowing Demonic Art" and the Banner of Ten Thousand Souls, setting out on a path of bloodshed and destruction, devouring all in his way. Starting in the Southern Region of the lower realm, he lies low and bides his time, growing stronger by devouring living beings. He fights a bloody battle against the Buddhist sects, dominates the Central Region, and ultimately smashes through the barrier between worlds by force while under siege, defying Heaven to ascend.
In the upper realm, Li Feiyu is reborn in the Land of Nine Netherworlds. His Dao Seed undergoes nine transformations, and he makes enemies of the Eternal Life clans, growing stronger as he flees their pursuit. His Dharma form reaches the heavens, and he reigns supreme within his domain. Traveling across the various Dao Regions, tempering his body and refining his demonic banner, he earns the fearsome title of Heaven-Swallowing Demon Lord. After becoming a Realm King, a Supreme, and even a Quasi-Emperor, he discovers that he and those who come after him are all trapped behind the despairing barrier of a severed path to Emperorhood. Reaching nirvana in a place of utter desolation, he once again breaks the laws of the world through sheer force, tearing open the barrier between immortals and mortals and ascending to the Immortal Realm.
The Immortal Realm is no paradise. His ascended body is reduced to the lowest rung, his cultivation arts are restricted, and an Immortal King crushes his Dao foundation with a single finger, nearly destroying both body and soul. In an abandoned wasteland, his demonic art reaches nirvana. He rises from the dust, devours immortal veins, and reforges his demonic banner, eventually attaining the Great Luo realm and once more standing among the Immortal Kings. Yet even after devouring countless beings and becoming a supreme powerhouse wreathed in imperial light, the realm of the Immortal Emperor remains as elusive as a reflection of flowers on water. Endless devouring and reincarnation bring nothing but eternal stagnation, and his extreme selfishness ultimately turns into hatred for the heavens and myriad worlds. Li Feiyu joins forces with other despairing Quasi-Immortal Emperors to unleash a dark upheaval that sweeps across the Myriad Worlds, harvesting countless billions of lives and using an endless blood sacrifice to break into the Emperor realm. Thus the story ends with the beginning of the Dark Age.
