MTL - Pirates: Play As Yujiro Fanma and Carry Shirahoshi Away - Chapter 156

Lingyun, a fierce and savage cultivation genius takes over a dead teenager’s body. Coincidentally, they are both named Lingyun. Set in a alternate version of the 21st century, teenager Lingyun has been killed by someone with a grudge.

- Description from Novelupdates

My name is Mikami Yuu, and I am a first-year student at the Soul Society, Shino Academy of Spiritual Art.

I have a friend who will be a little famous in the soul world in the future. His name is Aizen? Jiayishu?br />Different from this friend who has great ambitions and lofty ideals, my goal is very simple. Through hard work and diligence, I will graduate Later, he became the chairman of the thirteenth team of Goutei, and has since become a warrior class, living a life of lying down and sucking blood.

Until one day, a thing called “Cultivation Binding System” suddenly appeared.

Whenever Aizen improves his strength, my strength will be automatically synchronized to the same level as Aizen.

Then, what to do in the future is very clear.

“? Jiayi? You have to work hard. As long as you work hard enough, I can live the life I want!”

- Description from novelbuddy

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

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.