MTL - This Cannon Fodder is Covered by Me! - Chapter 19 I covered this Xueba

A former sporting rifle shooter genius transforms into the ‘Juvenile Butcher’. While originally supposed to have received the death penalty, he was instead fortunate enough to have entered a secret and highly regarded armed force, throwing himself into the ‘Nirvana Project’.

After a period of 10 years, he now has time to freely recover. Having trained until he had excellent military and martial skill, he sweeps through various military districts and returns back to his hometown. Under the monitoring of a beautiful female cop, he re-establishes his family’s bodyguard service, protecting beauties and moving unhindered, his achievements causing the fame of his outstanding, god-level bodyguard service to resound across the world!

- Description from Novelupdates

This is a world filled with despair, teeming with hordes of corpses, mutated creatures, poisonous plants, demons, and gods.The human societal system has completely transformed, with no justice, no righteousness, only might and slaughter.The strong can oppress the weak at will, human order has utterly collapsed, and the law of the jungle reigns supreme. In this world, weakness is the original sin!Some lucky humans have awakened extraordinary abilities, becoming Evolvers, and have risen to the top, possessing wealth, resources, beautiful women, and status.Qin Jun crosses into this doomsday world, awakening the Great Villain System at the start. As long as you are villainous enough, SSS-level talents, gene serums, and potential points are all within reach.Perhaps in the doomsday world, only villains can climb step by step to the peak…

In the year 2031, the earth has further advanced in its technological developments. Though there are democracies, republics, and several other systems of governance followed by various countries, there is still one country that adheres to the feudal system—the Arinphiam Empire.The empire is divided into three parts, where the royal family coexists with the central government to control the empire, keeping it as one of the strongest nations on planet Earth.The richest man on this planet belongs to this empire, where noble families still exist, governed by laws specifically made for them by the royal family instead of the central government.Marquess Avendial Croceaus has finally returned to the past, to the year 2031—a year before the tower's arrival—on the date where his downfall began.As he returns to the past, he discovers himself facing the initial setback of his life, where accusations of treason are soon to fall upon him.This world-building novel presents a completely fresh story with new ideas and plots, where the efforts of the main character lead him to become the one who changes his fate as a villain.Content warning: Adult R-18 Chapters without any warning, as they could be part of the story, a slow but well-paced story to provide the detailed idea about the world-building, a weak main character with the debuff of seven curses, making him even cut off from the chances of growth.

Born of a great family, world shaking genius.