MTL - What an Audacious and Sly Servant! - Chapter 55 oath

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

At a young age, I became a thousand-year-old bastard.

Ding! Congratulations to the host, you have obtained the phagocytosis synthesis evolution system.

An earth dragon was found in front, devouring synthetic evolution, the earth dragon tortoise.

From then on, my wonderful career began…

- Description from novelbuddy

There are a total of seven sins, and a revelation is made to a young man named Alex that he is destined to become a demon lord, more especially a demon lord of sin called LUST.

It's not like he can change that and because he always knew something about himself was different—not in a physical sense, well, maybe a little—and not in a mental sense—but rather because he is thrown into a demonic war that compels him to accept his new reality.

He was only aware of a difference in himself. Relating to him and the ladies who are drawn to him... Well, it was more or less like he was a magnet in front of all the girls, and all the girls were drawn to him like a metal.

An introverted girl has had enough of the isolation inadvertently formed by her self-imposed isolation. Things changed when she discovers that she has the ability to transverse across the fabric of our universe into the dimensions of multiple storylines. Not only do these storylines leave her with invaluable lessons – they also impart a portion of their power – if she is deserving of it. The time has come for Zhao Youyue to change her fate. She will be a Side-Character, or perhaps…something more!