Skeleton Knight, in Another World - Chapter 17Volume 6 -

What would you do if you were transported to an academy where becoming immortal was possible? Where magic spells and swordsmanship were your courses and fighting zombies and wars were your exams? Dawn Academy was no ordinary learning institution and Xiao Lin was about to find out how mysterious and exciting this magical academy really was.

Chi Yan had always had a weak constitution, and ghosts had always tried to kill him. He had tried many ways to change his situation, but it was all futile.

Coincidentally, Third Master Ye of Shiming City passed away, and a priest informed Chi Yan that Third Master Ye possessed the “look of demon,” Carrying a bit of this man’s ashes and installing an altar for him at home could help control the evil spirits around Chi Yan.

Left with no choice, Chi Yan took a gamble. Amazingly, it worked. However he didn’t expect that he’d be instead be haunted by the most persistent ghost of them all.

Obsessed with love, undying resentment, possessed by evil.

- Description from Novelupdates

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.

In an era when knowledge was banned, the physician Lyle had to be extremely cautious even in academic research, an invitation from the Andrei Academy materialized before his eyes.The Andrei Academy of Cassandale?Lyle peered closely at the tombstone before him, hissing,“Ah, the scholars here really know how to pick a spot.”