Becoming evil makes you ten times stronger, but becoming a demon gives you hundredfold strength - Chapter 559 - 404: Better to Leave First

Avo was born to destroy New Vultun. In a twist of fate, he’ll become its only hope for salvation. The gods were the enemy. The slaver. The chains. With dreams of paradise, humanity slaughtered them and stole their powers, opening the path to become more – to ascend. Instead, they nearly destroyed the world. Vast hive cities serve as the final bastions against the crumbling of reality. New Vultun is the greatest of them all, and within its borders, ascenders wage war to determine the laws of existence itself. The world descends ever deeper into ruination. Avo was born a weapon, a slave to his instincts and his masters. He and his brothers were made to burn New Vultun to ashes. Everything changes when Avo gains immortality and becomes heir to an impossible legacy. He must ascend the megacity of New Vultun. He must challenge the very tyrants that usurped the gods. He must finally free the world from chains.

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

[WSA 2025] To confront the threat posed by monsters and demons, humanity summons a hero endowed with a mysterious system and an unrivaled capacity for evolution. He becomes the last bastion of hope for mankind. However, one of his mistakes gives rise to a calamity far worse than the Demon King.This calamity is conceived in a dungeon, abandoned as a fetus by its mother, and raised by the Demon King himself. Upon the Demon King's death, all the restraints he had placed upon the creature are shattered. Thus, the hero's nameless son begins to lay waste to everything. The greatest calamity the world has ever known is born.

Dying and then meeting a giant God in the image of an Impostor from Among us in the afterlife was certainly something I didn't expect would happen.Getting reincarnated by it, was something I expected even less.And awakening in a world where heroes and villains run rampant, was certainly the cherry on top on this whole matter.But well, nothing I can do about it.