Monster Integration (Web Novel) - Chapter 3973 Birthday

Cho Ryu Hyang was good at math from a young age. When he enrolled into the The Theoretical Maths and Martial Arts School, the teacher, Jo Gi Chun, recognized Cho Ryu Hyang’s talent immediately and took him in.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

Transmigrating into a fantasy world, starting as a typical rich and handsome guy, he has a useless main character fiancé, a sister who knows the future plot, and a distant cousin who is the reincarnation of his nemesis, the Nine Heavens Mysterious Maiden.He becomes the final boss in a female-oriented novel, forcibly killed by the plot?Although he has a system that allows him to become stronger by binding with geniuses, Jiang Minghan states that as a gentleman who likes to stay calm and friendly, he just wants to be good to others and doesn’t want to be a villain.To avoid the fate of being overpowered by the female leads in the future, he can only walk further down the path of a villain.But unknowingly, when did he become the source of darkness, disrupting the eternal heavens?

I found myself possessing the body of a young master who everyone was eager to kill. I’m invincible, so let them try to kill me. It’s only for one second, though.