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.

[Ding, your frog was afraid of your death, so he went on a trip overnight and stole a shelter for you! 】

…

Reborn into a world of global catastrophe apocalypse.

In the face of global recovery, zombies, fog, meteorites, prehistoric creatures, glaciers, earthquakes, acid rain and other devastating global disasters, the only thing Ye Su has to do is to survive.

Unexpectedly, he got a traveling frog when he arrived. The frog was afraid of Ye Su’s death, so he simply stole a shelter!

Ye Su: “???”

But what’s even more outrageous is yet to come.

[Ding, your frog is afraid that you are not stable enough, so he stole the source of fire for you]

[Ding, your frog was afraid that you would be bitten, so he stole the antiviral potion overnight! 】

[Ding, your frog stole the Zanpakutō for you! Additional Asura – Blade Skill! 】

So, when everyone was avoiding zombies, disasters, despairing for food and water, Ye Su had already carried a big knife, drove a car, and came out for food!

- Description from novelbuddy

Transmigrated to a wizarding world.'But... what about the promise of wizards pursuing truth?''Why is it just a bunch of greedy people who seek power!'...Passing guests, please come in and take a look; if it's not the right fit, then feel free to leave.

Sally, in order to fulfill her original wish, entered Beast World and transformed into a little white mouse, also binding herself to the Offspring System.[The Dragon Lineage has gone ten thousand years without new blood.][How many points for the Dragon Lineage?][Five hundred million!]