MTL - Villain’s Delicate and Charming Wife - Chapter 34

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

My talent can be said above average but for my family I am useless. Six years after the incident that I caused I accidentally created a system.Now I wonder if I will fail again....with my new power I will make sure my cute little older brother, sister and especially my Father will pay the price of creating a monster.... Me

What if a wisp, with zero EQ about human culture and habits, gains the opportunity to cultivate and finally achieve human form? Now he can enter cities, experience technology, and fight his way to the top, right? In this universe where wisps are seen as nothing more than cultivation resources, a wisp stands up to challenge the wisps destiny! Not without causing a lot of misunderstandings on his way, of course…