Great primordial sin - Chapter 218

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

This novel is also known as Reborn In Space: Pampering The Genius Doctor And Businesswoman

In her past life, she had no one to rely on and died alone in jail.

But now, she has been reborn, given a second chance.

Got an heirloom.
Activated a mystical Space Dimension.
Studied medicine and became a genius doctor.
Opened a clinic.
Founded a company.
Bought a house and land.
Found her blood relatives.
Her worth became higher and higher.
Her fan club became bigger and bigger.

“Young master, the Zhao family’s young master faked an illness and went to future young miss’s place for treatment. . .” said a servant.

“Break his legs! Fail his organs! A fake illness? I’ll make him sick completely!” A man said.

“Yes! But young master. . . what are you doing?” The servant said, confused.

The man finished swallowing a bunch of expired pills and said, “I’m sick, gotta go find my wife for some treatment!”

- Description from Novelupdates

A genius schemer, creating an emperor!

“Only when your brother is happy can you be happy.”

She committed all kinds of evil deeds to make him Emperor. However, Artezia’s devotion was repaid with betrayal. It was the Grand Duke Cedric, a righteous enemy, that gave her a hand of salvation at the threshold of death.

“Devise a plan.”
“…”
“I can’t think of anyone but you who can reverse this situation. Marquess Rosan.”
“…”
“Lend me your strength.”

There is no plan that can reverse the already declining power and save the fallen empire. However, there is a method. To turn back time before everything went wrong.

With tears of blood she sacrificed her body to an ancient magic. This time, she will not fall.

Artezia, who returned to the age of 18 before death, resolved to become a villainess for the Grand Duke Cedric.

“Please give me your hand in marriage. I’ll make you emperor.”

In exchange for kneeling to the devil, the devil shall dirty her hands for you.

Get the power of the steel chain fingers in “JOJO”, form your own family force, and completely subvert the world of pirates!

I am BIG.BOSS, Mafia Victor!

- Description from novelbuddy