MTL - Lord of Souls - Chapter 43 How did you get promoted again! ?

Reiji Saeki, who lives in the north eastern countryside town, lost his life in an accident during summer vacation. ……But before he knew it, a mysterious ball of light hovered in front of his eyes in a world of whiteness. That ball of light was a magician from a parallel world, and is looking for a person qualified to inherit the magic they had created to prevent it from being lost. Reiji, who rode on that suggestion, now lives in the parallel world Elgin, with a new body and powerful magical power.

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

Shi Jin once read a book. It was supposed to be about satisfying the desire for vengeance.

The main character, also named Shi Jin, was the sixth son of his harem-novel-protagonist-like father. All was well—while his father was alive. But after his death, Shi Jin’s five elder half-brothers tormented him, eventually leading to his death. The protagonist was reborn, determined to take revenge, and… the novel was discontinued.

That day, Shi Jin almost spat blood and dropped the book into a shredder. The next day, he died in a car accident. Somehow, when he came to, he had transmigrated into a teenager, a youth also called Shi Jin.

There was only one problem. His father had just died. His older brothers were about to torment him…

Shi Jin: Let’s eliminate my brothers’ hatred, my goal is to keep my life!

- Description from Novelupdates

One of the top expert killers, tired of endless assassinations and having survived a cruel and suppressed life, decided to escape the world’s strictest assassin organization.