I Need Money to Level Up - Chapter 5 - 0 Village

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

One day, in front of my eyes appeared a silver-haired Goddess.

What kind of bullsh*t is this woman spouting?

“…What?”

No, I’m not.

Vahn was an atypical youth. Due to a rare mutation, his blood had the potential to target and attack ailments within the human body. Touted as a universal cure, people had elevated his status above the norm and given him the classification "Panacea". In the media, he was hailed as a great hero who would usher in a new era or human wellness. However, behind the scenes things weren't so bright. Being a unique individual, Vahn spent his entire youth locked up in a lab with various scientists and research teams using his body and blood to perform endless amounts of experiments. The only solace in his suffering was the various anime and manga made available to him between experiments. He often imagined himself as the protagonist in a world of his own, finally in control of his own destiny. For years he nurtured this desire, until at the age of 14 he died when an organization had tried to kidnap him from the lab...

In the end of the world, the fittest survive.

Come back from rebirth, seize the opportunity, just want to survive in the hopeless end times.

Three months before Mu Nan returned to the apocalypse, he sold all his savings to accumulate supplies, hoarded everything he could hoard like a hamster, and then huddled in his own house and lived a low-key life, carefully waiting for the apocalypse to come step by step…

- Description from Novelupdates