After the Fake Young Lady Stole Everything from Me, I Became the World’s Sweetheart - Chapter 399 - Three-Hundred and Ninety-Nine:

Happiness of the family >>>>>> World peace!? The curtain rises on another fantasy slice-of-life tale, brought to you by the “Hataraku Maou-sama!” team.

On that day, an emergency family meeting was called to order at the residence of the Kenzaki family, an ordinary family living in Tokorozawa City. A blonde beauty named Dianaze Krone, Diana for short, had appeared from a different world, in the living room of the Kenzaki family. “I, an envoy, have come to summon the Hero of Salvation, Kenzaki Hideo.”

Wait, Hideo is my dad! To think such a game-like situation would fall upon me, Kenzaki Yasuo, an ordinary high school student.

My father is a hero, and he saved a different world in his younger days!? There’s no way I can believe that this ordinary, middle-aged father of mine is a “Hero.” Diana looks at me, “The Son of the Hero” with a gaze filled with longing. My sister who saw that looks at me with a cold gaze… Before bringing back peace to the other world, the peace of our family is in big trouble! What is going to happen to my peaceful everyday life!?

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

Flatten the Devil's Palace, eradicate the demonic cult, slaughter the demon lairs, sweep through the demon realm, dominate the heavens and earth, control the three realms, be the supreme master of the mysterious sect, master of the Nine Yin, the 17th head of the North Star Sword Sect, the Heavenly Fiend Lone Star, the Supreme Sword Soul, the Supreme Infinite Mysterious Heavenly Wishful Great Sword Patriarch... Also known as Iron Egg, known for the wild history of relentless killing.

He was the youngest guru of martial arts as well as the perfect Mr. McDreamy of the most girls. He had mysterious absolute touch, clear-sighted observation ability and various outstanding talents.