My Pet Is a Holy Maiden - Chapter 39

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

Junpei Takeda, a high school student, is childhood friends with Noriko Tatsumiya and is bullied by Kido Shouta. One day, while bullying Junpei, they (Junpei, Tatsumiya, & Shouta) were suddenly summoned to a different world by the whim of “God”. Summoned Heroes with cheats, or so he thought. But it turns out Junpei’s stats were even worse than an average farmer. Tricked into a deathly labyrinth by the only one he trust, he walks the journey for revenge.

For ten years, Ryn lived in quiet exile with his wife Mira, far from a world overrun by supervillains. But when the flames of chaos reignite, he’s forced to return to the battlefield, stronger and deadlier than ever.By his side is Mira, his unwavering partner—devoted, ruthless, and hiding a darkness Ryn can't see.Enemies rise, old ghosts return, and war looms on the horizon. Ryn seeks justice, while Mira seeks to protect him... even if it means drowning the world in blood.Let them come.

The young lord of a small and weak country saves a dragon beside the sea one day.