Li Lun is a pagoda tree spirit/demon who gained sentience and power after cultivating for tens of thousands of years, eventually allowing him to take on a human form.

Throughout his long existence, Li Lun has repeatedly witnessed humans hunting, killing, and exploiting demons, regardless of whether they were benevolent or malevolent. These experiences shattered his belief that humans and demons could coexist.

Li Lun suffered profound losses that filled him with rage and regret—most notably the death of the one he loved. She was a sparrow spirit who used to perch on his branches back when he was still a tree. She would often rest there even after transforming into a human as woman. Once Li Lun took human form, their bond deepened, blossoming into mutual affection and a shared desire to protect one another. However, his beloved was captured and killed by humans—specifically, members of the ruthless Chongwu Camp, an organization that hunted demons/spirits solely to exterminate them. From that moment on, Li Lun came to view the world as an inherently unjust place for demons.

Over time, however, his resentment curdled into obsession. He came to believe that minor sacrifices were justified for a greater cause, that manipulation and murder were necessary costs, and that mercy would only lead to failure. He began manipulating humans consumed by suffering and greed, promising to grant their every wish while concealing the true price he demanded. Those who struck a bargain with him would transform into demons stripped of reason and self-control, driven only by an instinct to slaughter humans and sow chaos.

Eventually, a demon-hunting bureau led by a young master named Zhou Yichen succeeded in tracking Li Lun down. A fierce battle ensued, Zhou Yichen wielded the Yunguang Sword, a legendary blade passed down through his family. It was a sword capable of slaying demons, whether weak or powerful. Initially, the battle between them was evenly matched. Yet, unexpectedly, the Yunguang sword ultimately managed to pierce his body. Li Lun groaned in pain. Summoning his remaining strength, he transformed into pagoda leaves and seemed to drift away on the wind.

Once he was far from Zhou Yichen, Li Lun reverted to human form, he collapsed to the ground, coughing up blood and groaning as he clutched his chest where the Yunguang sword had struck.