Naruto System in One Piece - Chapter 378

Wang Xuan entered Longmao Square and was trapped in it. When he finally left, it turned out…

This is the last building on earth.

- Description from novelbuddy

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.

The strongest Demon Lord dies, and reincarnates as a human. Not only that, he because of various incidents turns into the hero’s best friend.

Follow his journey as he tries to help the hero escape his fate, and on the sideline to conquer the continent while he’s at it.

When she was rejected by her fiance, everyone laughed at her. Little did they know, she actually loved her fiance's uncle, a trillionaire tycoon, for a long time.Later, she had four doting brothers, numerous secret identities, and a husband who was madly doting on her.Fu Shiyan smirked, pulling her into his embrace, “Dear, when shall we have our third baby?”