Zenith of Sorcery - Chapter 3. New Generation

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates

What is a young teacher to do when stuck with four cute little students in a beast apocalypse?. It's obvious, raise himself four little wives!!Well it's not his fault after all. They are the ones initiating it. As far as he's concerned, he's the victim of the story.“These four little devils, they are definitely after my back!”

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

Monsters lurk in the night, but what if something else hunted them? An incident in his childhood left Velik an outcast with a racial subtype that thrives at night and unique class called [The Black Fang], which focuses on just one thing: killing monsters. He’s good at finding them, and he’s good at slaying them. For ten years, he’s been gaining levels and sharpening his skills on the thousands of monsters infesting the wild lands of the frontier. For ten years, he’s kept a lonely stretch of towns safe. Despite his efforts, this year has seen an explosion in the monster population, so much that he’s no longer capable of protecting everyone by himself. This draws the interest of another monster hunter, one that’s professionally licensed, but he seems more interested in investigating Velik than anything else. At least with him there, Velik is free to finally explore the mysteries of the deep wood, where he believes the source of all monsters resides. Every answer he finds leads to new questions, and not even Velik himself knows the truth of what happened on that fateful day. One thing’s for sure: not even the monsters are safe in the dark.