The Simple Life of Killing Demons - Chapter 9Book 3:

In a world where strength determines one’s future, William, an orphan with no extraordinary talents, faces a grim destiny—until a brutal attack leaves him clinging to life. Instead of death, he awakens to a mysterious and powerful entity lurking within his mind: the Shadow System, a game-like interface that promises him unimaginable power. But this power comes with dark secrets, and refusing it would mean his death. Forced into a pact with a voice that can hear his every thought, William must navigate a dangerous new reality where shadow abilities and celestial power collide. As he enters the prestigious military academy, his newfound abilities draw both allies and enemies, all while a deadly conspiracy brews in the shadows. With the odds stacked against him, William must unravel the mystery of the Shadow System and decide whether to embrace the darkness within—or be consumed by it. His journey from a bullied outcast to a potential god will challenge not just his survival, but his very humanity. Power always comes at a cost—will William be able to pay the price? “What am I?” William asked the system. The system’s voice echoed in his head, cold and indifferent. “You are nothing.”

Mana finally arrived in our world after being delayed for unknown reasons, causing the evolution of everything that had life.

Humans, plants, and monsters all evolved, ushering the planet into a new era in which old laws no longer applied and the only law in the world was the rule of the jungle, where the strong preyed on the weak.

It was a question of whether we, the 'rulers' of the land, would be able to maintain our position and adapt to whatever came after our planet's awakening, and if we did, was that the end?

Suddenly appearing in a different world, it looks like I got caught up in a Hero Summoning. And of course, I’m not the Hero, but it’s another guy……and while being very cautious and scared of the cliche of the cliche-like development, I was thrown into the maelstrom of war……or not.

The Demon Lord? It was defeated a thousand years ago. Hero? He’s just the main actor in a festival. Nobles? They’re kindly taking care of us. The Demon Race? They have good relationships with Humans. Wars? It’s already 800 years since the last one. Monsters? The Guild and Order of Knight are taking care of them. Return to Earth? It is eventually No-Risk.

What I’m planning after being caught up into this? I’m gonna enjoy the life in a different world as much as I want to, go on a cultural exchange and sightseeing, and after experiencing the festival that is only held once every ten years……I shall go home safely.

The other world was――at Peace.

A kind world where the three races, the Spirit World’s Magical Races, the Celestial World’s Divine Races, the Mortal World’s Human Races, they are kind neighbors to each other, with everyone living a peaceful and fulfilling life.

But although I wished to peacefully spend a year before my return, for some reason, the heavyweights of this world keeps gathering around me, and……