Mortals Are Forbidden from Cultivating Immortality

(I'll revise the blurb before I start posting. This is just a note of the premise for now. It should be a Lovecraftian cultivation story set in ancient times, or maybe a tale of the strange.) Blurb: A hundred years ago, a ban on cultivation was decreed. Since then, no one in the city has dared mention the word "cultivation." Only those who pass the imperial examinations may obtain cultivation manuals. Everyone else is branded a monster, yet people still repeatedly break the ban in pursuit of immortality. After receiving an anonymous tip, a constable breaks into the Lu residence in the middle of the night, only to find that all hundred or so people in the household have vanished without a trace. They search the entire estate and finally find someone in a room sealed shut with planks nailed across every side. The nails in the boards are completely rusted, and the dust inside is thick enough to write in. The room has been sealed for at least a year, yet the young man on the floor is still alive. His skin is warm, his breathing steady, and he looks no different from an ordinary person. The moment the terrified constable draws his sword, it suddenly dawns on him: this isn't a person. It's a monster. When Xie Shangzhi wakes up, the back of his head is digging into a pile of hay, and iron bars stand before his eyes. Cultivation. That's the charge against him, the jailer says. And in three days, he'll be executed. Xie Shangzhi has no weapon and no idea what's going on. All he remembers is one simple spell. He tries to channel his spiritual energy. A few pieces of straw float up, then turn into a little paper figure in his hands. The paper figure is palm-sized. It tilts its head, then falls into deep thought under his earnest gaze. Then it turns around, carefully spreads out the straw for him, and gestures for him to go to bed early. Xie Shangzhi: ... Why is this a domestic-life spell?! That night, the shadow on the floor swallows the jailer, rises up from the ground, and grins at him. "You look delicious." The little paper figure bravely steps in front of Xie Shangzhi. Xie Shangzhi looks at himself, then at the little paper figure, which doesn't even reach his ankle. He's touched, but maybe the little paper figure should just run away while it still can. As the shadow demon pounces, the paper figure transforms into a paper sword in his hand. It guides him in a powerful downward slash, and the shadow demon screams before vanishing into nothing. Xie Shangzhi: "...Huh?" The next day, the county magistrate leads a crowd in kneeling before him. "Immortal, please save the thousands of lives in our county!" Xie Shangzhi: "...Huh?" No, seriously, he really doesn't know how! The little paper figure is the gong's avatar. Theme: Creating a beautiful life