ShadowBound: The Need For Power - Chapter 308: He Is The Reason

At the Tristain Magic Academy, her classmates call bumbling witch-in-training Louise Francoise le Blanc de la Valliere “Louise the Zero.” During an important coming-of-age ritual, when each student must summon their own witch’s familiar, Louise confirms her classmates’ opinion by accidentally conjuring up a normal teenage boy from Japan. Whether the two of them like it or not, the laws of magic bind them as master and servant forever! A hilarious novel with romance interwined.

Xia Zhijun got the title ‘study god’ after scoring first place in the whole city. He’s the model of a good student in a teacher’s eyes: good grades, good manners, and quiet. When he wasn’t smiling, his entire body emits a cold abstinence aura. The girls only have the guts to look from afar and not get close.
Later, it was rumored throughout the entire school that even the study god would fight and hit on girls. Whoever dared to provoke his girl, he would teach you how to be a person at every minute. The night of the graduation ceremony someone saw him blocking Gu Siyi in the corner. He didn’t stop kissing even when she cried. He bit her lips and said in a raspy voice, “I’m going crazy…”
During college finals, Gu Siyi almost bursted out crying, “I’m such a failure. I won’t be able to find a good job in the future…And if I can’t find a good job, I can’t provide for myself…”
Xia Zhijun played with her pink earlobe and remarked, “I’ll take care of you.”
After they graduated, Xia Zhijun created a research company and Gu Siyi became the boss’s wife.
The commercial rocket, “Star of Siyi” was successfully launched. So everyone knew that the new technology superstar, Xia Zhijun has a wife who he spoils a lot.

- Description from Novelupdates

My whole life, all I wanted was power.

I churned the world into rivers of blood and eventually gained the title, “Demon Lord of Strength”. However, all this became useless when I lost to a party of heroes.

But what can a loser say? As I laid dying, I was forced to listen to the hero’s gibberish:

“If you are born again, I hope that you will live a kind life!”

But huh? When I opened my eyes again, I was back in the past.

“What do I have to do to live a kind life?”

This is the beginning of an ex-Demon Lord’s journey to live a kind