My Childhood Sweetheart is Actually a Monstrous Tyrant

Yu Pei is a transmigrator who entered the world of the novel The Weakness and Salvation Guide sixteen years ago. Originally chosen by a system to fill the role of the villainous second female lead after a reborn person killed the original character, she lacks spiritual power and cannot recall any spells due to a childhood injury. Raised by the Mermaid Clan after being adopted by their leader, she eventually joins the Spirit-Taming Sect as a low-ranking servant disciple to await the start of the plot. Her primary mission is to guide the story’s key events while avoiding erasure by the reborn antagonist. The system rewards her with attack points for hostile interactions, which can be used to open a rift back to her real world.

The story begins at Demon God Mountain, where Yu Pei is forced to dig for spiritual stones alongside her senior brother, Xu Muzhi. Xu Muzhi mocks her incompetence, but Yu Pei remains cold and calculating. She knows this location is the seal point for Su Zhan, the novel’s ultimate villain, whose heart was removed and hidden within the mountain. The original plot dictates that Yu Pei will be injured here and saved by the male protagonist, Wen Yunhe. However, the arrival of Chi Shu, a powerful young master from the Ghost Realm, disrupts the timeline. Chi Shu is guarding the mountain and immediately confronts Yu Pei for trespassing. Instead of fleeing, Yu Pei deliberately provokes him, accepting his sword strike to accumulate attack points. She then claims to be waiting for her senior brother, buying time until the original protagonists arrive.

Wen Yunhe, the female protagonist Jiang Yuan, and their senior brother Shen Zhongyu are captured by Ghost Realm officers after being trapped by a Spider Demon. Yu Pei is detained with them in Demon God Pavilion. While imprisoned, she uses a soul-switching technique to separate her consciousness from her body, sending her spirit to locate Su Zhan’s heart. She discovers the heart is not a monstrous organ but a small, fluffy, black creature resembling a puppy. The creature is lonely and vulnerable, reacting with distress when Yu Pei retreats. Meanwhile, back in the physical world, Shen Zhongyu reveals he was poisoned by a spider bite. His arm is turning purple, and he hides the severity of his condition. Yu Pei recognizes the symptoms from the novel, knowing that Shen Zhongyu is destined to die from demonic poison because he cannot heal himself.

Chi Shu interrogates the prisoners, suspecting Yu Pei of spying on the stone pavilion. He detects no spiritual traces on her, leading him to believe she is innocent. He compensates the group with spirit stones and agrees to write a letter of explanation for their failed demon-hunting mission. Yu Pei requests a rematch with Chi Shu to gain more attack points, a request he grants due to her apparent dedication to cultivation. As the group prepares to leave, Shen Zhongyu asks Yu Pei to help carry the unconscious Jiang Yuan. During the descent, the group is ambushed by the Spider Demon, which traps them in an illusionary tower. The Ghost Realm officer leading them is arrogant and dismissive of Yu Pei’s warnings, refusing to use proper demon-expelling techniques.

Inside the tower, the Spider Demon’s swarm proves nearly invincible, regenerating from the corpses of its kin. The Ghost Realm officer charges ahead but finds himself running in circles within the illusion. Shen Zhongyu organizes a defensive formation with Wen Yunhe to protect the others. Yu Pei observes that the magic aura is concentrated around the corpse pile, suggesting the demon’s true location. The officer’s reckless attack disperses the poison into the air, threatening to suffocate the group. Shen Zhongyu prepares to sacrifice himself to create an escape route, but Yu Pei notices the structural weakness in the illusion. The narrative ends with the group trapped in the spider tower, facing the demon’s wrath while the Ghost Realm officer remains oblivious to the danger he has brought upon them.