Becoming evil makes you ten times stronger, but becoming a demon gives you hundredfold strength - Chapter 95 - 84 A World of Difference

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.

They called him useless. A Class E farmer in a world where strength meant survival.Betrayed by the woman he loved, beaten by a power-hungry King, and left to die like trash, Isaac thought his story had ended.But death was only the beginning.Beneath the earth, sealed for thousands of years, a forgotten being awakens, an ancient force of ruin once feared by angels and demons alike. When Isaac agrees to its desperate offer, he doesn’t just survive… he becomes something else. Stronger. Colder. Hungrier.Now reborn with a forbidden power that rejects magic itself, Isaac walks the line between man and monster. Each time he unleashes the Abyssal Overdrive, his strength grows, but so does the Corruption threatening to devour what’s left of his soul.To protect the innocent, he must become the very thing they fear.To destroy the kings who shattered his life, he must embrace the darkness within.Enemies will fall. Secrets will unravel. And when the kingdom of Carreon learn that Isaac is still alive… it will already be too late.The world shunned him. Now, it will kneel.

Mediocrity is the normal state of most people, and some of them can’t even reach the normal state~ A young man from a small town, ugly and inferior, disliked by relatives and friends, mediocre grades…

All these changes started with a beam of light going to the university train, and the boy was bound to the high-quality male god system.

The days are getting more and more hopeful, and the system is really fragrant:

As long as you learn, you can modify your own bugs;

As long as you do good deeds, you can get corresponding banknote rewards;

As long as you are praised, you can get relevant talent blessings;

…

This, it’s hard not to love, okay!

- Description from novelbuddy

ln the Higher Realm.{Ehhh! It’s started?} an entity exclaimed.{Yeah, but like, what the hell—she gave the golden finger to him? Of all people, someone useless and a scheming bastard?} another shot back, clearly not having it.{Someone Immediately Stop him he's corrupting the system!} An entity roared before they could even get ready for see how had had been chosen!___On Earth.[System Integration... 1%A wicked grin spread across his face. This was his chance—a chance to do something no one in those web novels and mangas and animes had ever done. To corrupt the system!minute later....[System integration... 85%...][System integration... 99%...][Integration complete!] It ran one last time...“Did I succeed?”And so the journey started.