The Extreme Alchemist of the Mighty Cauldron - Chapter 1742 - 1839: Demon Saint Battles Demon Tree

18 years have passed since I was born as Allen, the eldest son of an earl in this world, while still retaining my memories of the present world. This world is peaceful and a stable society. The only extraordinary thing is that I was reincarnated into a world that is lenient on the existence of concubines. I selected a silver-haired maid as a sex slave and second wife candidate from among 10 candidates after a strict fellatio practical exam. I then lived an erotic life at home and at school as an attendant, but my reincarnated life is so fulfilling that I'm worried it will explode, as my busty childhood friend, a noble girl who was unsuccessful, ran for the third wife candidate, and my stepmother, who was my virgin partner, was sold off.

Fate is weird. Of all the people in the world, why would it select me to send to a different world?

And what is it trying to do? Put up a show by giving me a system? But oh well, what do I care.

The previous owner of this body was a cripple and looked down on, but now I can slap their faces with my system.

Young masters? Get out of my way!

Princes? Geniuses? Oh please. I have a system. That does not mean anything to me.

I know that I am not the greatest. But fate gave me a cheat system, and I am not wasting it.

I am going to do whatever it takes to conquer this world. Fate forced me to do this. It isn’t my fault if I cause some ruin on the way.

The Queen of the elves wants to bear his child, the vatican’s saintess is his maid and the empire’s princess wants to elope with him.

But his only concern was his delusion of taking down the creator of the world!

- 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.