My Mother Has a System but Won't Use It - Chapter 13: Luck Trade

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

CautionTaboo 18+Banished by failure and despair, a virgin loser wakes in a new world with a forbidden power—the Lust System. To survive and claim a rare herb that could save him, he must seduce, corrupt, and conquer hearts across worlds. Pleasure is the key to power…and survival.

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).

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