Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 7Book 2: -1: The Result of Effort

It’s a affair between a loyal dog servant and his master.

- Description from Novelupdates

This book is also known as: “How Programmers Turn a Crappy Game into a Timeless Classic with a Single BUG”Recently, the president of Nitiandang, Gu Fan, once again fell from grace due to a minor bug in his new game.As a top-notch designer in the industry, all of the games designed by Gu Fan have very distinct characteristics:At first, players felt that these games were monotonous, dull, and purely revolting garbage.However, once players discovered a major bug, the gameplay underwent a drastic transformation, rendering them sleep-deprived and unable to quit!So, players once again launched a major debate over “whether this is actually a bug or a game mechanic.”In response to this, Gu Fan clarified in an interview with all seriousness:“Hello everyone, I'm the game designer Gu Fan, but you can also call me by my English name: fan·gu (means rebel).”“I want to reiterate firmly that these so-called 'core gameplays' were not part of our company's original design—they are bugs! It's just that we didn't fix them because the players liked them!”

Humanity was living peacefully on Earth for millions and millions of years until the day unknown monsters from beyond space invaded them.

When humans were about to disappear, some people with abilities came out to the light and shared their knowledge and powers with the world, and together, they managed to push back the invaders during a terrible war that had lasted for years.

This war had created many orphans, and among them, Kye had lost everything, even his parents. And the only thing he received from their death was a pale-looking necklace.

However, once the necklace finally activated, a system was given to him, and his life changed completely.

The system gave him quests to do, and Kye complied. He was getting stronger every time he achieved them, until the day it gave him a weird quest.

[You have one day to kill the one who had sinned. If you do not kill, you will die.]

Xiao Ze, who was dedicated to the people and vowed to become a generation of Ming Jun, accidentally fell on a little lady.
The little lady was born beautiful and lovable.
So Xiao Ze accepted his life and got the name of fear.

ps:
①The male protagonist has no concubine, and he is dedicated to serving the country.

- Description from novelbuddy