Shadow of the Abyss - Chapter 31: Slaves

After the last elemental high tide ended, the world entered the “Great Ebb Tide Era”, and countless races such as elves, giants, orcs disappeared in the long river of history. However, the continuation of life has its own way. After a long time of accumulation, the blood of ancient alien races gradually merged into human beings.

You have the blood of a giant, become my warrior, and I will let you look down on the common people again;

You have elven blood, join me, and I will let you feel the call of the moon god;

You have the blood of an ancient dragon, show your surrender to me, and I will make you the apex of the gods!

I am the blood lord, I have the ability to awaken the power of blood, my name is Robin.

This is a system, lord, war article, I hope you like it

- 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.

Xie Tao had always believed in science until one day, a meteorite smashed into his yard, forcing him to bind to a heroic world saving script. The worst thing was that the script didn’t even follow common sense.

Others become superheros while he became a super-nanny. So in his left hand was a “Cub Encyclopedia” and in the right, a small milk bottle to feed the small cub clinging onto his leg.

Today, Xie Tao is trying his best to save the world.

- Description from Novelupdates

A good-for-nothing who went missing for three years finally made his comeback! He successfully inherited ancient powers that defy the heavens! Proficient in medical skills and spells, the city was at his whim—everything was in his favor!