Shut Up, Malevolent Dragon! I Don't Want to Have Any More Children With You - Chapter 129Vol 3. : Empire’s Top Female Marksman

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

I started off as nothing, just a mass of consciousness that slowly evolved. Just your average overpowered existence hungry for a multiverse adventure.

Year 2022, December the 1st. This was the day it all began.

Labyrinths had started forming all around the world, hundreds and thousands of people lost their lives as casualties.

Mutations followed after, occurring amongst the people, they began awakening super powers, the same for animals.

However these mutations brought along a virus. It quickly spread amongst the dead as they began to rise. Humanity had begun its fall.

Gray who had given up all hopes of living life, was granted a system with a special ability. On the very same day, of the outbreak, he was consumed by a labyrinth.

By the time he had gotten out, a week had passed. It was hell all around. A virus had broken out from the mutations, the dead were walking and spreading this virus.

However this was only the beginning.

Over time the mutations began to evolve and people learnt that the through the cultivation of their powers, they could improve their abilities.