Mushoku Tensei (WN) - Volume 1

Transform into Divine Dragon and dominate the world!
He is the only Divine Dragon in the sea who founded an underwater Dragon Palace.
With Crawfish Soldiers and Crab Generals as his followers, wild sharks and gigantic octopuses as his subordinates, he is the dragon that rules the city.

- Description from Novelupdates

After all, transmigrators of this era were no simple matter. Some became slimes, others turned into treasure chest monsters, and some were even reduced to mere skull--such things were all commonplace.It was nothing more than playing a villain, Shiayar didn't care. Wasn't it only natural to pay some price to become stronger?[Destined Great Villain System][“Let this world feel the agony!”][Newcomer Mission: Let the young and naive Grand Duke's daughter of the Azure Garden Dukedom, Miss Silvia, experience the betrayal of her loved ones and, amidst the pain and despair, complete her transformation and rebirth.]

Caelith doesn't want too much in life, a clean home, a happy mother, and maybe a girlfriend. Raised in the Stormont manner, one of the highest ranking noble household in the kingdom, he grew up a bastard, mistreated and abused by the main lineage.At the tender age of sixteen nobles undergo a divine ceremony, receiving the opportunity to be blessed by the gods however he receives Nothing.Caelith struggles in this world but at the end of the day, He is Nobody, and he has Nothing.

A world where the [Demon King] was defeated by a [Hero] that came from another world. People carelessly forgot about their fear of the [Demon King] and of monsters, living in peace.

In a forgotten and run-down cave in the mountains, a new monster that should not have been born was given birth.

The monster’s name was the [Black Ooze]. It was nothing exceptional other than its black color, an ordinary slime.

However, this slime had the special characteristic of being able to take the abilities of the living things it swallowed. It preyed on an insect that had paralytic poison, as well as other animals. Following that, it attacked a human, obtaining his knowledge and [Desire].

Before long, the monster established its target as the female mage that came to explore the cave.

This world still wasn’t aware.