MTL - Start with 3,000 Demon Gods and Become Invincible - Chapter 135 Abnormal combat power! do whatever you want

I am Master Siwei, and I speak for arcane arts.
This is an era of heroes and heroines.
This is an era of great changes.
In the end, it will be an arcane era opened by me.

- Description from Novelupdates

The strongest wizard Alfred, in a hero’s party, subdued the Maou and in the process took a cursed arrow to the knee.

Even with the hurt knee, Alfred’s still the strongest wizard ever. So…

「We need a chief for our newly created knight squad!」 「Could you help us as our guild manager?」「We need someone to rid us of the dragon that resides in the North Mountain!!」

Alfred just wanted some time to rest and recover, but no one would LEAVE HIM ALONE!

Because of that, Alfred wished to spend time recovering in a small country village that no one knew about.

『Need a guard in Mulg Village. Wolves and boars attacking the village. Payment is food and board. *Village has a hot spring.』

「THAT’S THE ONE!」

So, the strongest wizard in the kingdom…decided on living the slow life in the country.

Marcus Manfred dreamed of joining the United States Army. That dream ended the day an accident took his life.But he woke up and met a Goddess who told him that he can be reincarnated with a weapon system. He accepted it and was reincarnated in another world.The Military Weapon System, grants him access to modern weapons and equipment. Rifles. Tanks. Fighter jets. Even warships. But everything has a price.To grow stronger, Marcus must take on requests from towns, nobles, and kingdoms: clear monster nests, hunt demons, repel invasions. Each completed quest earns him funds to expand his arsenal.But this world is not Earth.Magic bends the rules. Dragons rule the skies. Demon armies march in the dark. And medieval kingdoms do not take kindly to a man building a private army beyond their control.In a world of swords and magics, can Marcus survive using his modern weapon cheats? Or will magic crush modern firepower?

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.