Superman Termination Manual - Chapter 524 - 260 Bai Zini I Have Two Friends

In the past, the giants of the heavens and the gods were destroyed after the reincarnation of the world! Cruel curse, eternal hatred, Tan Yun is determined to never sink again! For the sake of loved ones and relatives, from now on, step on the corpse of the enemy step by step to surpass the peak! Defying the sky, killing all worlds, I am the only one!

- Description from novelbuddy

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.

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.

Leiyin accidentally crossed into the One Piece World, and accidentally obtained the Naruto System.