Revenge of the Sixth Young Lady - Chapter 344

A young man plagued by recurring nightmares finds himself visiting a blind fortune teller, who sends him to a world of martial arts that looks a lot like the wuxia stories he used to read.

In the sky of this world, a tome shines every now and then, revealing the hierarchy of mighty beings that seek power amid troubled times. Determined to unravel the mysteries of his involuntary journey and the secrets of the world he has ended up in, he endeavors to ascend the tome’s rankings, all while looking for a path back home.

Official Chinese blurb

Wandering the jianghu with a blade and wine, where beauties’ grace is filling one’s mind.

A youth, saber on his back and wine gourd at the waist, strides forth, yet the jianghu of his heart seems only more elusive;

With each flipped page of the Tome of Troubled Times, decades of nights soaked in rain pass over the jianghu.

As he suddenly turns to look back, he finds that the mortal world has shattered in his wake.

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

In the year 54 of the Konoha Calendar, two super geniuses appeared in the Konoha. One is named Uchiha Itachi, and the other is named Akihara Kagura. One is a tool of the village, willing to sacrifice everything for Konoha, except for his brother Uchiha Sasuke; the other claims to be a tool of the village, also willing to sacrifice everything for Konoha, including Uchiha Itachi's brother, Uchiha Sasuke.

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.