Days with the demon queen - Chapter 15: Mastermind

In the ancient land of Yamato, seven powerful clans rule, each upholding their own traditions and strength. But when one clan seeks forbidden power, the balance of the world is shattered. Legends tell of warriors destined to rise, of a hero who will walk the sacred path, and of a battle that will shape the future of Yamato. As alliances are tested and enemies emerge from the shadows, the line between justice and power begins to blur. Will strength alone decide the fate of Yamato, or will a greater force change its destiny forever?

Among the demons, the supreme ones are called “Great Saints.”

A young man leaves his mountain village and travels around the world. By unceasing efforts, he finally becomes a legend of the age.

- Description from Novelupdates

The simulation is over, and the entry is obtained: a showdown!

Looking at this entry, Zhao Meng was stunned.

“How should this term be used?”

“Hey! Here’s a wounded fox!”

…

A few years later, a woman who looked like a fairy appeared in front of him, and said:

“My lord, I’m here to repay my favor!”

This book is also called “Starting from Transforming Monsters”

- Description from novelbuddy

Yuuta was the weakest, most average guy on Earth—barely surviving college, working a part-time job, and raised in a quiet orphanage with no real family to call his own. But everything changed the night he had a vivid dream... of marrying a stunning, powerful Dragon Queen from another world.He woke up thinking it was just a dream. Until she showed up in his room—with wings, horns, and a daughter who calls him Papa.Turns out, it wasn’t a dream. And now Yuuta’s life is anything but normal.With half her power sealed, the Dragon Queen—Erza—is stuck living in the human world, adapting to cramped apartments, dishwashing shifts, and the chaos of Earth. Yuuta, once a lonely soul, suddenly finds himself with a family, a responsibility, and feelings he never knew he was capable of.As fatherhood, monsters, magical secrets, and mysterious enemies creep into his life, Yuuta must rise—not as a hero, but as a man who has something worth protecting.