MTL - Ask Sword - Chapter 8 oil lamp

The King of Hell sentences you to death by midnight, but I can ensure that you live past morning.

The young man, Qin Lang, received the inheritance of a poison school by chance. He uses poison to kill people, uses poison to save people and he uses poison to chase beauties. With body of ancient extinct poison and a body of a martial artist, he walks around the city, and wanders around in the underworld.

- Description from Novelupdates

A one-of-the-kind advanced game? Liberty Online.

Dungeon master class that needed to protect his dungeon core?

No system in place to revive monsters by magic, it's up to him to keep them alive.

Unfortunately, that's not all he has to worry about.

The whole population of immortal players has set their sights on his precious dungeon? And

Woah Dungeon got conquered in the game. Many celebrated, but he cries blood tears for his mistake.

Not able to handle the pressure, he died in remorse for how stupid he was his whole life.

But then something miraculous happens. He got reincarnated back in time - one year after the game’s release!

Armed with knowledge from his previous life, He will use this chance to achieve his every dream.

He strives to reach a height where no one dares to touch or even think about touching him.

This is the story of Roan - a man who will use all his power and strength to become king of Liberty Online!

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.

He was a wealthy and mysterious financial backer who had appeared before her when she needed money the most. After the courtship, she took the money and left.