MTL - Traveling Through Three Years, You Told Me This is a Horror Game - Chapter 99

A child was born unable to cultivate Inner Strength. In order to gain his father's attention and regard, he resolutely chose the painful and difficult path of cultivating Outer Strength. As spring gave way to autumn, time flew by, and the child grew up... he became a young man. What truly changed his destiny was a mysterious Crystal Stone formed from a meteor—the Meteor Tear. This Meteor Tear, unbeknownst to the young man, merged into his body, and like a caterpillar transforming into a butterfly, the young man metamorphosed... And with that transformation, everything changed. And his father finally came to realize the astonishing strength of the son he had never truly invested his Heart Power in...

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

Untolerated by heaven, a boy was restricted by the most powerful spell.

He accidentally acquired a painting inhabited by nine souls that claimed to be immortal.

Then, the legend of a strong young man who violated heavenly principles against the course of nature began.

- Description from Novelupdates

It was a hasty, arranged marriage.And on their wedding night, he ran away.He lived for ten years under a false name, becoming one of the 7 Great Masters of the Continent, but returned home when he heard news of his father’s passing.There, he found his wife, whom he thought had already left, whom he had only seen once before.She was still as beautiful as the first time he saw her.