[Book Transmigration] Colluding with the Protagonist

Irregular updates. As a fine young person of the 21st century (read: corporate drone), Qiu Qingchen wakes up to find himself inside a novel he once read. The character profile provided by the System plainly states: [Cause of death: alcohol poisoning]. Qiu Qingchen wears a deadpan expression. “...Heh.” Well, he was dead, and now he's been transported into the novel. All he can do is grit his teeth and carry on living. What? He's a sect elder? And a background character, at that? Isn't that even better? jpg Got a goldfish brain and can't remember the original plot? No problem. The System provides all five deluxe volumes, ready to consult whenever he likes. His personality is worlds apart from the original body's? No problem. The System says there are no penalties. Live however you want and be true to yourself. So Qiu Qingchen plans to start a relaxed, leisurely new life in another world. But then Zuo Yu, the protagonist: Martial Uncle, are you there? I've brought you food! Qiu Qingchen: ?? What happened to being a background character? What happened to having a peaceful life? Why does he run into the male lead right away? No thanks. We are not doing this, author. Half-Demon Daoist is a reborn cultivation novel about revenge. The protagonist, Zuo Yu, diligently cultivated for over twenty years and finally formed his Golden Core, only for his own master to carve it out and use it to forge a magic weapon. Only as he lay dying did he learn that he carried the bloodline of the demon race. Zuo Yu died with hatred in his heart. When he opened his eyes again, he had returned to twenty years earlier, to the moment he first became a disciple of the True Lord Fuqiong. The Golden Core was still in his dantian. Given a second life, he refuses to repeat his past mistakes. He keeps a low profile, bides his time, and waits for the chance to kill his enemy and avenge the core that was taken from him in his previous life. But unexpectedly, his elegant and radiant Martial Uncle has undergone a sudden change in temperament! Has someone taken over his body, or is this a test? What unspeakable secret lies behind it all? Qiu Qingchen: Don't worry. I won't get in your way, so don't waste your time on me. Zuo Yu: !! Zuo Yu: Martial Uncle has been so good to me, and I have no way to repay you. If you really want to sell me, I'll just have to accept my fate. Qiu Qingchen: Good heavens, the protagonist wants to sell himself to me as a leg-hugging accessory! A small, bitter, vengeful rabbit in the beginning, becoming a devoted, persistent puppy later, pursuer x a short-tempered, sickly, self-centered receiver A love story written as a reborn revenge tale, but read as a mystery. Theme: 108 ways to slack off