Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 10 Chapter 2 part1-2

It is an era of artificial superintelligences, interstellar travel, gene medicine, and virtual reality worlds. Far into Earth’s future, 15-year-old Gu Ding is a student of Cerulean Military Academy by day, and tavern waiter by night. His ambition: Become the space pirate with the highest bounty offered by the Universal Federation Government. With the help of Neptune, a neonate super-intelligence, Gu Ding finds himself thrust into a galaxy of shadowy organizations, political underdealings, and otherworldly forces that lie beyond human comprehension…

Damien Julian is an 18-year-old loser, who has been bullied and mistreated his entire life, at home, he has to deal with his abusive father, and at school, he is constantly been bullied by delinquents, and to make things worse he is always looked down upon by his peers, till one day a mysterious screen appear before him as it said.

[The world has seen the lingering evil in your heart]

[Would you like to be one of the nine demon kings of this world]

[If so what are you willing to sacrifice?]

In the heat of the moment, Damien made a deal with the world, that he would give up everything he owns, or do anything it wants, and in exchange, he shall be reborn as a new Demon King, and what the world required from him as payment was.

[In exchange for power, become a slave of the world, and act as an anti-body for all eternity]

At that moment, Damien agreed, but little did Damien know, that becoming a slave to the world meant he has to be its immune system, what that entail is, that anything that threaten the world must be destroyed even if he has to wipe out humanity, to save it, or assassinate historical figures to bring fort balance or even manipulating events that can potentially end the world, to save the world, this is the story of a necessary evil, not the story of a hero who cares for others.

Wang Bo was fed up with his job being a programmer, especially because of all of the nights he was working overtime without pay. His boss had given him a mysterious game to beta test in his free time, which had granted him possession of unclaimed territory in New Zealand with which to improve to his desires. After a certain event in his company, he ended up quitting his job. His lack of goals and curiosity eventually led him to buy a ticket to New Zealand, in order to see if the unclaimed territory given to him in the game was actually real. Watch, as he develops this beautiful, fertile stretch of land into prosperity, by building villages, farms, schools, hospitals and more.

- Description from Novelupdates

Qin Chen was transmigrated to the Taiyi Holy Land where he became a servant in charge of sweeping the floor. However, on his 16th birthday, he was rewarded with a system where he was rewarded whenever he signed in at a new place.

When he signed in at the Empire Ruin, he was rewarded with the strongest Chaotic Holy Body and the Chaos Emperor Scripture.

When he signed in at the Demon Sealing Land, he was rewarded with the Probationary Royal Armies.

When he signed in at the Alchemy Palace, he was rewarded with the Divine-grade Alchemy.

When he signed in at the Herb Garden, he was rewarded with an Immortality Elixir.

When he signed in at the Empire Palace, he was rewarded with the Emperor-grade Divine Art, Revival.

…

Qin Chen thought he could just spend the rest of his life signing in at different places until he became invincible.

However, when the ruin of the Great Kingdom appeared inside the holy land, people from other holy lands, prestigious families, and even ancient empires gathered to defeat the All-Powerful Demon King who appeared with the ruin. The Demon King had killed countless people and had planned to destroy the Taiyi Holy Land.

Qin Chen was left with no choice but to step up. When he killed the Demon King with a single slap, he sighed, “Why do you guys have to force a mere servant to act?”