It’s Lonely To Be Invincible - Chapter 248 - Let the huge mace do it’s work

A side story series featuring the girls of Kyoukai Senjou no Horizon.

In the Celestial Empire, a land ruled by Immortals and stalked by Spirits and Beasts, a young girl from the slums of an unimportant city is found to have the Talent. In the great Sect of Argent Peak, she will take her first unsteady steps upon the way.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

Born to a mother on death row and subsequently raised in the prison, Gu Tianyou did not have what most people would consider a ‘normal’ childhood. Instead of the usual math and history one might learn at a public school, he had criminals for tutors. He received regular lessons from notorious serial killer, Dr. Miao, and earned protection from the respected Master Long.

With such a unique background, Gu Tianyou graduated from the Police Academy with little difficulty, and was assigned as an undercover cop. But will the skills he learned from a lifetime of being cared for by criminals be enough to help him take criminals down?