Monsters Are Forbidden from Falling in Love!

In a silent universe, all kinds of immortal monsters were exiled to exist for eternity. Until a System appeared and offered them a deal. [If you follow the plot through to the end, you can gain true freedom.] The monsters said, "Sounds good." [1. The One in the Dark]: It lurked in the shadows, feeding on fear and growing ever stronger. No one could see its true form. Little by little, it became the most terrifying monster of all. The System said, [Then you’ll fight another terrifying being and die, while the protagonists live happily ever after.] The One in the Dark said, "Okay..." As it roamed the darkness... it caught an unexpected, enticing scent. Delicious. The monster came to an abandoned factory and saw a man standing in the dark, holding a cigarette between his long, sharply defined fingers. He faced a dozen or so people across from him, his expression nonchalant. Its heart pounded. It didn’t understand what was happening to it. Without thinking, it slowly extended a shadow from the darkness and licked the blood on his arm. Si Shen raised his eyes. There was no one around, but he sensed something in the darkness, secretly watching him, following him like a shadow. To be "rescued," he chose to cooperate with that unknown presence. After escaping, he discovered... the darkness seemed to follow him everywhere, quietly tidying his messy room, occasionally making him a cup of tea, and even... wrapping itself soundlessly around his ankle while he slept. Its damp, clinging, greedy gaze grew more and more intense. He had caught the attention of a monster. Much later... The head of the Si family was in danger on his way home. Something in the darkness silently protected him, then stammered in a distinctly inhuman voice, "Don’t be afraid..." The man lowered his eyes, a smile slowly spreading across his lips. It seemed he had fallen in love with the monster. [System: ???] Wait, weren’t you supposed to follow the plot? Why did you two get a romance storyline? No. The next monster can’t fall in love again. [2. The One with a Secret Crush]: He died and became a terrifying ghost, growing stronger with every passing day. The System said, [Then you’ll fight the evil spirit bent on destroying the world. You’ll both die, and humanity will finally live in peace.] The ghost said, "Okay..." He came back to life, seemingly having lost all memory of his death. His face always seemed deathly pale. It seemed he fell in love at first sight with a calm, self-possessed man. It secretly took photos of him and covered the walls with them. It would quietly scheme to run into him, gazing at him with eyes full of love. It would get hurt protecting him, and learn what he liked to eat. Everyone said it truly loved him. At last, the man was moved and chose to be with it. But people kept appearing in secret, finding him and saying with terror in their eyes, "Your lover isn’t human. It will destroy the world. Please help us kill it." The man never believed them. Until one night, he opened his eyes and saw his usually gentle lover gripping a grotesque creature by the throat, its voice icy as it asked, "Were you going to hurt him?" The evil spirit’s eyes widened as it desperately shook its head. Lost in love and unable to pull itself away, the lover sneered coldly. "You’re still pretending you didn’t? You deserve to die." Its hand tightened, and the evil spirit that had once terrified countless humans disappeared. The man closed his eyes and sighed. He really does love me. [System: ??? How did you two end up in a relationship again?] #Even if you’re a monster everyone fears, I’ll still love you# [An anthology. The top and bottom are different in every world. This is a bottom-focused story, and every couple gets a happy ending.] Theme: Love is poison, and also the antidote you willingly embrace