Isekai Maou to Shoukan Shoujo Dorei Majutsu - Volume 10 prologue

She died in her prime as the Queen of Song.

After being reincarnated, she becomes a simple trainee.

Losing her former glory? It doesn’t matter—no one can compete with her voice as a beautiful singer.

Mocked by her lowly birth? It doesn’t matter—her true identity is enough to make the whole world tremble.

She owes huge debts? It doesn’t matter…

A powerful boss once whispered to her, “Your debt will disappear if you become my woman.”

But the proud her would reply, “I’m sorry. I would sell my art, but not myself.”

- Description from Novelupdates

“Welcome to Perfect Life Simulator!”

“You can choose to simulate your own life or someone else’s life to find solutions to many life problems!”

…

A watch handed down from his deceased parents allowed Su Wu to start a future life simulator.

He thought that he could really use this simulator to lead a perfect life without regrets, but unexpectedly things developed in another direction.

In the future, as long as there is light, there will be evil spirits that kill people;

Hanging in the sky and covering a city, it leaves a city without red lanterns of living people;

The scarlet eye that can use a mobile phone to spy on the specific location of others…

Will such a future really come?

…

“you are dead.”

“This simulation is over.”

- Description from novelbuddy

Ryu Han-bin, the main character who fell into a new world after being chosen as a ‘suitable person’.

Because of the error in the guidelines, the training is repeated endlessly…

A ritual gone wrong gave him the world's deadliest Class—now all he wants is blood.Zeth stole the most powerful ritual magic in the world from a mad cultist. A Class that's fueled by the blood of his enemies and human sacrifice. One that's illegal to use, punishable by gruesome death. And now that he has it, he's faced with a choice: hide away for the rest of his life from those who would hunt him down, or embrace the power, becoming the hunter to get revenge on the murderer that stole his friends' lives.For Zeth, that's no choice at all.His enemies have to die. And he plans to use every drop of blood, eldritch ritual, and demonic summoning he can to kill them.