Can you recommend some novels that include plots where the protagonist turns black or his personality collapses, or plots that describe characters who are as emotionless as machines?

I recommend the following novels to you: 1. The main character, Su Changcun, had activated the Dark System and his personality collapsed, becoming cruel and heartless. 2. [Pokemon: Legend of Brother Zhi]: After the protagonist, Jiu Mozhi, was imprisoned and turned into a dark person, he became a cold and resistant training master. 3. In " Quick Rescue: Female Supporting Actors Are All Courting Death ", the main character Xia Qing remolded her three views and picked up her moral integrity in order to save the supporting actress, while the supporting actress disregarded her life and death because she was blackened. 4. " Quickly Pierce My Demon Host ": While the protagonist constantly travels through different worlds to save the blackened male god and prevent the world from collapsing, he also discovers the source of the blackening in his body. 5. " Big Boss, Put It On Quickly: The Men Who Have A Secret Love For Her Are All Darkened ": While the protagonist saves the blackened character, he must also find a balance between interests and feelings. The above is my personal recommendation. I hope you will like my recommendation.