Moto Sekai Ichi'i no Sub-chara Ikusei Nikki - Chapter 88: Thinking while not thinking.

Zhang Ruo Chen was the sole male heir of one of the nine emperors of the Kunlun Field. Ruo Chen’s father was known to all as the “Enlightened Emperor”, however Ruo Chen didn’t just leech off his status as emperor’s son. He proved himself to be a dragon amongst men, possessing a heaven defying body, and managing to cultivate to Greater Perfection within the Yellow Horizon Realm, at just the young age of 16.

But even though he stood at the summit of the younger generation and had a boundless future, he sadly died at the treacherous hands of his own fiancee at a young age.

Reincarnated 800 years later in the body of a young boy who shares his name, he found out his former fiancee already unified Kunlun’s Field and built the First Central Empire, and was now known as Empress Chi Yao… Empress Chi Yao—Her Majesty governed the mortal world and enjoyed prestige in all directions as well as an eternal life.

Zhang Ruochen stood outside of the Imperial Ancestral Temple, looking at the statue of Empress Chi Yao, and the flames of hatred burned in his heart. “After I practice for 13 years, I shall send the empress to her doom!”

- Description from Novelupdates

After transmigrating, Chen Yu found himself in a highly militarized world. But the “will of the world” had concluded that he was an intruder and put a curse on him.

[Host, host, I am the System, I can help you conquer the world and the witches with various personalities.]Xi Mu: Hmm... Isn't this an action game? When do we start slashing?[Right... This is an action game, but I suggest that the host also try to seduce the witches along the way, there are generous rewards.]Xi Mu: What rewards?[Of course, the perfect romantic experience!]Xi Mu: No need, I've already played through the romance plotlines. Now I just want to go on a rampage and speedrun the game.][...]

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...