I could have chosen any class, but I chose the most perverse one

I wanted everything. But I got nothing.
And I died. Frustrated, dissatisfied, unfulfilled. The darkness in my heart is as black as the darkness in which I am immersed in this oblivion.
[[ CHOOSE YOUR CLASS ]]

When I opened my eyes, I became someone else.
Different appearance, different voice, much younger, and in a different world.
I'm the villain of this story, and I have some peculiar abilities.
I could have chosen any class, but I chose the most perverse one...
I will use the abilities and powers of my secret class to obtain everything I desire and assert my dominance over others.
It will be a lot of fun!

WARNING:
This grimdark story is a Hentai focused on Plot.
The novel contains heavy s*x scene, depiction of r*pe, s*xual abuse, torture, physical and mental.
This novel is R-18 and for ADULTS ONLY.
All characters engaging in s*xual conduct are over 18.
The story features very heavy, dark themes.
None of the conduct described is encouraged.
It's written from the the perspective of evil-aligned characters.
Any similarity to actual events or persons, living or dead, is purely coincidental.
English is not my first language, so I apologize in advance for any grammar or syntax errors you may find in this novel. I would be grateful if you could point them out. Thank you in advance for your patience.

GENRE:
Adult Ecchi Fantasy Harem Hentai Isekai LitRPG Mature School Life Smut

TAGS:
Adventurers Alchemy Antihero Protagonist Battle Academy Blackmail Cheats Confident Protagonist Demon Lord Demons Dungeons Evil Protagonist Game Ranking System Harem-seeking Protagonist Hiding True Abilities Hiding True Identity Level System Male Protagonist Master-Servant Relationship Modern Fantasy R-18 Secretive Protagonist S*xual Abuse Slave Harem Succubus Weak to Strong