MTL - Shadow Rogue - Chapter 15 : Killing Night! (under)

One day, a tower appeared in the skies of all the major cities…

Apollo Kaiser, a boy who bore the unlucky fate of being unable to grow strong, was condemned by his family.

Discarded by his mother and abused by others, Apollo gives in to his rage.

However, this action results in his death. Many would believe it to be the end, but Apollo's death was a required catalyst.

The Demon Monarch System finds its heir and attaches to his soul, bringing him to a new world where he starts his journey to supremacy.

This difficult journey rife with conflict, conquest, and brutality shall serve as Apollo's temperance.

Watch as the heir of the Demon Monarch rises above all, conquers Sin, subjugates unthinkable enemies, and even brings about the destruction of worlds!

The rise of the next Demon Monarch begins...

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

Once I’ve become Immortal, then my attempt to conquer the world shall begin.