One Piece: The Devil Fruit Collector - Chapter 200: You Seem a Bit Panicked, Little Brother?

Those people killed her grandmother, murdered her younger brother, trampled the people she deeply cared about, and even took her own life.

It was because she trusted her ambitious stepmother and half-sister;

because she mistakenly believed that womanly virtue is to have no talent;

because of her noble status and origin….This is what caused her death.

Buried in river water, Ouyang Nuan, gritted her teeth and spoke, “I, Ouyang Nuan was wronged in death. Even if it takes forever, I will become a devil, and in the next life, will not let you off!”

When she once again opened her eyes, Ouyang Nuan was sent back in time to when she was twelve years old. Around this age, her forehead was scarred, her brother fell into the water, and in three years she will be married…

In this life, she will try to change everything to guard and protect those she cares for from those with treacherous intentions. She will live a glorious life!

- 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.

Tong, a sinner who was suffering endless torment in hell because of his mistake he had done in his previous life, was giving other chance to redeem himself by the devil.

A rich young master, a hedonist, has the Hedonist Sovereign System forced upon him. Follow this hedonist on his adventure of becoming a Hedonist Sovereign through doing real life quests, filled with action-packed battles and hilarious moments. A lazy and slothful hedonist doing exercise in the morning? A spoilt and self-entitled hedonist starting from the bottom as a salesperson? Watch as Qin Feng is changed by the Hedonist Sovereign System, inside and out!