Master Smith Under Ministry of National Defense - Chapter Prologue

The Mc reincarnates in a world of magic and adventure as a Leech, follow his adventure in this mysterious and exciting world as he goes from the weakest creature to the shadow being that everyone is afraid of. Will he pursue the path of strength alone? Or without realizing it he will become the king of the greatest empire that ever lived.

This story is about the romance that blossomed between a beautiful princess and several courtiers, told through the various positions they experienced together.

A river song, triggered a legend of the rivers and lakes.
Tian Zun’s life motto: “My sword is the truth.”
Shen Lang’s life motto: “To serve people with morality, those who are dissatisfied are dead.”

- Description from uukanshu (translated)

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.