Dragon Tamer - Chapter 16 - Nan Lingsha

Every family has that one person who is born as a sacrifice. For her family, that person was Selene Vale, who was to become a spare for her younger twin siblings success.Due to her innate shy and kind nature, she was not able to connect to her family every since she was young. So, despite her rich background, Selene Vale never felt like a part of the family and was often regarded as the 'First spare' or even 'defective'. That did not change even when the world fell and Apocalypses happened.Selene Vale's first life ended trying to protect her twin siblings, the only people who had yet to abandon her. That was her end......but it wasn't.Due to her sacrifice, Selene Vale awakened her system and innate power and was given another chance at life and survival. And this time, she vowed to free her siblings from their parent's cruel influence. If she was able to do that, then she would be happy with that.But unfortunately, that was not all she did. She also ended up attracting the attention of the big-boss of the Apocalypse, the only L-ranked hunter and the hope of humanity....and also, a long time friend she would rather forget about.

A Federation Colonel with abnormal thoughts was locked in a dark room and met a little looney.

“Your whole body emits a scent that I dread (covet) and fear (desire).”

A frigid Colonel X little looney roommate: A sweet story of interstellar travel

- Description from Novelupdates

The day dungeons appeared on Earth, everything changed! From ordinary beasts to monstrous ones, attacks were common throughout the globe, and no one was safe.

After countless studies using these beasts as subjects, Humankind developed a serum capable of awakening incredible abilities in humans, leveling the battlefield.

With the serum came heroes and villains, those who wished to use their powers for good or bad.

The Garmony Upper School was a place for the elite with the sole purpose of creating heroes to fight the villains and explore more of the dungeons after the beast attacks increased for no apparent reason.

Damian Romero, a youth who received the serum after turning 18, yet got no unique ability. It was not uncommon for one to not receive power, but it was still a blow to one's pride.

He went rogue after the news, drinking alcohol and having a good time with women, and it was at that moment, when he was putting his toy to play, he got a surprise.

[All-in-One System Unlocked]

Damian's unique ability was a system with multiple functionalities, but after he studied it, it seemed this system worked with a different type of coin called Erotic Coins!

Improve his body? Buy any item or unique ability from his system's store? All Damian needed was Erotic Coins, and he knew how to earn them!

Reborn and returning, he possesses medical skills, can practice immortality, has a slave who is the king of killers, and a maid who is the school beauty pursued by everyone. Even casually taking out a piece of trash can shock the world. His return has set this world ablaze.