MTL - Midnight Cinderella - Chapter 79 One extra

A good-for-nothing man married a beautiful girl but was kicked off the bed on the wedding night. Furiously, he wrote a bill of divorce and ran away.
He was schemed a car accident in which he nearly lost his life. However, it turned out to be a blessing. He swallowed the soul that passed through the outer world, thus obtained superb medical skills and martial arts.
Later on, with the silver needles and invincible martial arts, he embarked on the road of counterattacks and was committed to his great dreams.

- Description from Novelupdates

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

I am an extra. That is an undeniable fact. As a mere extra in a fantasy world filled with sparkling heroes, charming princesses, and mysterious antagonists, my existence is merely to serve as a backdrop for them. But I, Arkan, will not remain silent! Why be satisfied with being ordinary, when I can be extraordinary?In this world, I might be just a herb shopkeeper who doesn't even get to be in the main dialogue. But somehow, my life began to change after I accidentally obtained an Artifact That Extra Characters Should Not Be Able to Have.Now, with a power that invites more trouble than anything else, I struggle to avoid the attention of the main characters... or steal their attention?