MTL - I Formed The El Cat Investigation Team In Pirates - Chapter 176 "King's return"

He—an enigmatic and cold-blooded soldier with a mysterious background.
She—a ruthless and bloodthirsty spy.

This novel is also known as The Yun Family's Ninth Child is an Imp!

She was an unprecedented assassin, a trump card deadly agent, but transmigrated through into Ye City’s number one prodigious good-for-nothing young miss.

I am an ugly woman? I will break out from my cocoon into a gorgeous butterfly that will blind your snobbish eyes!

I am useless piece of heap? Lightning in my hands, I will smite you to a well-cooked crisp!

Her greed and lust for money had no end. She is lewd to the core with no bottom in sight, sworn to have love fortunes blossom all around her. However, a certain someone holding a blade in the left hand and a sword in the right hand began cutting those love fortunes one by one!

The person smiled with perked brows, “Little Ninth, it looks like I have to let you become occupied!”

- Description from Novelupdates

Her rebirth gave her a second chance at life. She was back with a vengeance and wanted to make those that had harmed her pay. But to those that helped her, she wanted to repay them. Her evil stepmother? She would slowly pull out her claws, one by one. Her evil stepsister? She would crush her pride. She thought that by getting her revenge for her past life, she would be happy in this life. However, she never would have thought that danger would chance upon her time and time again. The hatred from her clan and whether their bloodline would continue to exist, lay solely on her shoulders. Luckily, on this thorny path, someone had always been protecting her. “Third Prince, have you ever regretted being with me?” That person laughed lightly and peered at her with a loving yet weary look, “As long as I am together with you, I have no regrets.”

There’s a legendary Bishoujo Game that has become popular among Japanese gentlemen.