Percy Jackson : The Odyssey of a Primordial. - Chapter 8: Hecate

Traveling to a different world, a bizarre, mysterious and vast world unfolds in front of Zhao Ji. He wants to run hard in this vast world and live a free and easy life.

- Description from novelbuddy

Xiao Ran transmigrated to a fantasy world. As a dungeon guard in the Celestial Dungeon, with a special floor called the Purgatory meant for powerful demons and martial arts experts, he faced a huge challenge from the start. The Eldest Princess acquired a forbidden martial arts technique and was banished to the Purgatory. However, no one was powerful enough to restrain her. All the dungeon guards were defeated. Xiao Ran stepped up and declared, “Your Highness, it’s better for you to behave yourself on my territory” and effortlessly subdued the Eldest Princess.

He progressed from imprisoning the Eldest Princess to delivering the Great Xia Kingdom from the evil clutches of various demons and evil martial arts experts.

…

Xiao Ran was the mastermind behind the scenes.

Transported to a rural family in 1973, where eating required food stamps, dressing needed cloth tickets, stepping out asked for a letter of introduction, doing business was considered speculative profiteering, and securing a job demanded an urban household registration. She, a young girl from the countryside, faced an indifferent mother, a troublesome younger brother, and an elder sister who often had poor ideas. Life had become insufferable.Memories from her past life are mostly forgotten, yet the myriad of objects in her magical storage ring baffles her greatly.

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.