Global Reincarnation: Only I Know the Plot - Chapter 22:

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.

The most dependable (sarcastic) assassin -- Gao Xuan.Developing himself with an inventory of powerful gear. A master of biding his time, backstabbing, and brutalizing weaklings.Don’t love me. Nothing would come out of this.I am an assassin without feelings.

I am the master of a certain dark guild.

Including me, there are only 10 other consistent members in this guild. However, all of them are like daughters to me… is what I think.

Since this is a dark guild, we act without standing out too much. However, it seems like everyone has been acting a bit too weird recently.

They’re acting really weird… eh? What? [Presenting me the whole world]?

In a world where its inhabitants can destroy a city wall single-handedly, the empress has a kirin as her pet, and the imperial palace of Great Xia has a pool containing a dragon. There is also a Sword Mountain where spirit swords occasionally leave in search of a master .

Bootlicking the empress, Ren Baqian ascended to the apex of life.

- Description from Novelupdates