From Abyssal Invasion to Bursting Stars with a Single Sword - Chapter 18 - Traitor Task

The MC (Minato) is a college student who died in a plane crash and was reincarnated in a fantasy world. He was raised alone in the wilderness by his succubus mother, and now he tries to make his way as an adventurer.

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

On the dawn of a fresh New Year, an ominous figure emerged, shrouded in a guise of an angel but harboring the malevolence of a devil. With a chilling voice, it proclaimed, [Every month, you humans will be thrust into a perilous quest. Your survival hinges on overcoming 20 grueling rounds.]Suddenly, I found myself ensnared in this dangerous survival game, a grotesque merry-go-round where every turn carried the stench of death. Yet, I was not without any defenses. I possessed an unusual power: the power to regress 100 times, a chance to rewrite my fate.I stand on the precipice of my final regression, and I swear, ‘This time, I will conquer it. I will emerge victorious.’I’m no longer the insignificant shuttle that I once was. Today, I shed my former self, the one who had reached the pinnacle of power. Today, I am reborn for the last time as Black Scythe, a rookie player, a novice that once again will be become the Grim Reaper!

Six months ago, tens of thousands of black phantom towers appeared all over the world, floating above the cities. Chemists, physicists, religious people… all of them could do nothing.