The Villainess Is Shy In Receiving Affection - Chapter 241: Side Story 2 –

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

This was the era that belonged to various powerful bloodline warriors, the fervorous era where magic powers and warrior energies were the deciding factor of dominance! With endless ardour and unstoppable courage, a grassroot nobody could also shine and live like a boss!

However, he did not know that he was not raising just a harmless pet, but a biological weapon secretly made by the government… a real monster.

As a former librarian, Rand felt that he had been living an ordinary life, the one that he had reclaimed unconsciously every single day.

Recently, he has been a little upset because the pet fish he accidently brought home to raised seems to have undergo some strange changes

Well, it turned into a merman.

- Description from Novelupdates

Traversing worlds with the Immortal Sword slaying demons, it was not until a monkey who claimed to be the Monkey King appeared before Lu Yu that he realized he had come to the world of Journey to the West. Striving for supremacy along the Human Path, the secrets of Journey to the West unrevealed, cutting off heaven and earth, the Three Realms were isolated.