Underneath the Silhouette - Chapter 12: Taste of Blood

The handsome Emperor falls in love with a Knightess! Knightess Poliana loses to the Acreian Army and despite her struggles to survive in a male infested military, she is now about to die. But then, the young king of Acreia sees her efforts and tells her: "I have a dream, I wish to conquer the world and become an Emperor, would you like to join me?"

Throughout this current life of mine, I will pay no attention to my past lives, nor will I seek future lives. I wish to live vigorously, to pay back debt of gratitude and fulfill duty to avenge, to defeat valiant heroes from all species, and to proudly laugh at all the Gods and Demons of the Six Path of Reincarnation!

- Description from Novelupdates

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...