In the last years of the Yong Dynasty, the way of heaven was in decline, ghosts and resentful spirits roamed the streets, and evil cultivators caused chaos everywhere. People in the world are as afraid of monsters as tigers, but they don't know that the greed, ignorance, anger and resentment deep in the human heart are the most powerful evil spirits in the world.
Lu Yan, a modern criminal psychoanalyst, came through his soul. When he opened his eyes, he was lying in a pile of corpses in a mass grave. He had nothing but a half-broken copy of "Inner Demon". He has no innate ability, no sect backing, and no unparalleled opportunities, but with the ability of psychological profiling that is engraved in the bone marrow, he can accurately dismantle the demonic nature of people and pinpoint the weaknesses of all parties.
Others rely on breathing and grabbing treasures to practice, but he prefers to use inner demons as a ladder and calculations as a blade. He started by subduing evil ghosts, using mountain spirits to eliminate evil spirits, using water demons to control water transport, and using painted ghosts to derail the righteous path. The world denounced him as the leader of the devil, but the demons and ghosts secretly respected him as the "Xuanjun" and were willing to be driven by him.
From the lord of a barren mountain to the leader of the demon alliance that rules the north and the south, Lu Yan competes with the Xuanmen of Zhengdao and the Si Tianjian of the imperial court. He set up iron laws to restrain his troops from violating common customs, punished false immortals and evil officials, and created a third realm in the gap between the human and demon realms.
As the power expands, the truth that has been hidden for three thousand years is gradually revealed: the so-called righteous way to eliminate demons is just a reincarnation harvest set up by the ancient existence of Tianmu; the "Inner Demon Barrel" in the hand also hides the shocking secret of the fall of the previous lord of demons.
The countdown to harvest has started, and the identity is as secret as a hanging sword. Between heaven's persuasion to surrender and the devil's temptation, Lu Yan always sticks to his true heart. He does not believe in the way of heaven or the way of demons, and uses modern thinking to understand the world situation. Amidst the tug of desire and the bottom line, he strives to find a way for thousands of living beings to survive.