Ultimate Cash System - Chapter 89: Aura.

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

Sirens: a name derived from an ancient creature, used to describe those who could charm, lure, control, and heal others by singing.

Subjected to live the life of a siren, Aria had experienced, seen, and heard many horrific things. Broken beyond repair, Aria resigned herself to death, when suddenly…

The Grand Duke, Lloyd Cardence Valentine, arrived and whispered, “Should I kill everyone here?”

“If you need me, just call me. Your song will always reach me, wherever you are.”

In the end, Aria called the devil, bringing death to all those present, along with herself.

“Let’s fall down to hell together.”

And with that, Aria breathed her last and died… only to return to her 10-year-old self.

Now that she had a second chance at her life, Aria was determined to change her fate, as well as the cruel fate of her saviour, Grand Duke Valentine.

And so… Aria proposed to him with a marriage contract.

She sold her soul to the devil and vowed to protect him.

The young duke took the contract from her hand.

“So, where should I stamp the seal?”

* * *

“You said you’d divorce me within 10 years.”

The grown-up villain leaned in, hovering his head before he kissed her tenderly over her crown.

“Now that we’re adults, we should sign another contract.”

One day, a handsome young man died in a car accident. He suddenly wakes up and find himself in an unfamiliar place, but what surprised him most is that he is taking over someone else’s body.

Kanda Kyoichi transmigrated to Konoha and became a temporary instructor at the Ninja Academy. Fortunately, he awakened the Mentor System.By teaching others, he could earn rewards.Thus began Kyoichi’s career as a “teacher” in the ninja world.Shisui: “Sensei’s unique interpretation of the Will of Fire has given the Uchiha Clan a true sense of direction!”Asuma: “The essence of the jade lies in protecting the people, with the advanced leading the way for the less experienced. Only then can Konoha become stronger!”Kakashi: “He’s my life mentor. He transformed Konoha!”...Years later, in the memoirs of Kyoichi, now the Hokage, he wrote:“I honestly just wanted to be a life mentor!”