Evil-Natured Husband, Don't Tease! - Chapter 313

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.

Over a million years ago, the first human contracted with the first Spirit. Ever since then, Spirit use has become commonplace. Humans used Spirits to carry items and start fires. Eventually, even start wars. Thousands upon thousands of years past and one day, one human did the impossible. He transcended his mortality and ascended to the realm above.

After traveling to Little Garden, Su Jin, who had just obtained the divine status and became a quasi-god, suddenly had a forum invitation in his eyes.

Butterfly Chanel Megumi: How to kill ghost dance at night? No misery?

Aizen Kuyousuke: How to take out the collapsed jade in Rukia Kuchiki?

….

Questions popped up one by one, and Su Jin subconsciously replied: Thank you for your invitation, people are in the small garden, they have just become gods, and the answers are anonymous.

- Description from novelbuddy

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.