Lord of the Truth - Chapter 1027: Matching opponents

The villainess sees herself executed in front of a large crowd by the order of the emperor (her husband and the one she loves). However in the next moment after her death, she is back in the past. Monique is sent back into the past because of her brutal memories of her previous life with a prince who was engaged due to their similar age. When Empress grew and looked at the past, she killed her emotions to live as an Empress and remained one emotion, that was sickening affliction. Where in her next life, she made new connections in order to avoid getting executed again…

The strongest King of Soldiers returns to the city of flowers, becoming his fiancée's cohabiting bodyguard!

With the memory of a Level 200, Tier 3 Mage. Lu Yang returned back to his life ten years ago. Destiny made a joke with him. He was betrayed and everything he worked for was taken away. He had to get it back.

The game’s money making methods, dungeon strategy, legendary quest, equipment source, secret blueprints, combat skills. He knows all. See how a reborn player with his brothers swept the country, burned the world and created the legend of The Fire God!

- 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.