Mistress Of The Evil Forest - Case 126: Correlation.

A young juvenile’s dantian was sealed since childhood. He can learn all elementary laws and master all martial art techniques. Various Kings strive to reach the heavens, new warlords rise together simultaneously, great races stand with thousands of numbers. From the moment that youth awakens, Everyone will shiver in his presence…….Humans unfair to ME, millions of corpses on the ground.

Qiao Zhenzhen spent a lifetime, only to later realise that she was the true heroine of a novel. According to the original plot, her life was supposed to be smooth sailing and blissful. But the envious transmigrated second female lead played her cards step by step, and took everything away from her!

After experiencing the divorce of her parents, and miserably failing the college entrance examination, she gets kidnapped along with her little follower of a male lead, Chi Shen. In the end, she came out as the only survivor.

Everyone believed that this was a blessing in disguise, not only was her life saved, but the pervert stalking her for the last three years was also gone! A freak like Chi Shen, who had a weird and eccentric personality, always stank of fish and grease, was better off dead. Everyone said that she ought to be grateful, but none of them knew he died protecting her.
Before he took his last breath, his dying words were-

“Don’t be afraid of me.”

That sentence, mixed with the smell of greasy fish and blood, flashed in her dreams every night for the next decade.

Reborn back into the senior year of her highschool, she walked to the youth in the corner, and in front of everyone’s eyes-

“Don’t hideaway in the dark if you don’t want me to be afraid of you.” The youth pursed his lips, his pale face steadily losing color.

Qiao Zhenzhen smiled: Be nice to me, and I shall allow you to stalk~

- Description from Novelupdates

Kai was a 17-year-old dropout. A NEET. A background character in real life with nothing to his name but bitterness, novels, and guilt. After his parents died, he gave up on the world. People were fake. Dreams were pointless. And that one novel he kept reading? He hated it especially the main character, June. Perfect, noble, always standing tall. Everything Kai wasn’t.Then, one night, a voice asked: “What if you did meet June?”He said yes, half-asleep and half-mocking.Now he’s trapped in the novel. Isikeid. But he’s not June. He’s not a hero. He’s not even in the main cast.He’s an extra in the background of a world he knows too well and he’s had enough of watching things play out the same way. This time, he’s going to change everything. Whether the world likes it or not.

Corporate slave Alexander dies with only one regret—not finishing the fantasy novel in his hands. Fate has a twisted sense of humor when he awakens as Alexander Flamingo, the perverted villain destined to be expelled and killed in that very story!Armed with complete knowledge of the original plot and a mischievous “Harem King System,” Alexander plans to rewrite his fate. No longer the one-dimensional pervert of the novel, he'll use his future knowledge to manipulate heroes, seduce heroines, and rise from disposable villain to the true mastermind of this world.The system grants him power through every relationship he builds—but can this calculating reincarnator use his second chance to avoid his predetermined death and become the ultimate Harem King? One thing's certain: this story won't follow the original script.