MTL - System Supplier - Chapter 25 It scares you to hear the name

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

Qi Condensation. Foundation Establishment. Core Formation. In the current world, only these three realms are known to be achievable. Nascent Soul is but a legend and the realms above it lost to the the long river of time. The modern era is known as Cultivation Civilization, a balance of power and civility, excess and moderation. While cultivation remains a secret practice, it has long since exposed itself to the mundane world, quietly intertwined with each facet of society. While the world appears to be at peace, what lies underneath is a conflict between human, cultivator, and demon, brewing for ages and waiting to implode. Yet in the wake of humanity’s rapid industrialization, qi—and consequently cultivation—is dying.

After her rebirth, Yun Shifei returned to her fifteen-year-old self, just when she became the true daughter of a wealthy family.The well-behaved and timid Shi Fei only wanted to live her own small life well.Who knew she would get involved with the Great Demon King.In her memory, this big shot was extremely ruthless, squandering the family fortune, watching his brother die coldly, and sending his father to prison.But now, the big shot is quiet, obedient, easy to bully, and loves sticking to her.Yun Shifei's heart softened, and she tried hard to protect him.Yet one day, the little poor thing she sheltered pulled her into his arms to kiss her.She was utterly shocked.He looked innocent and said: 'I heard this is a way to express liking. Don't you like me?'That's what it means, but why does something feel off?!

Due to investigating an arms case, he was forced to become a gigolo, from then on, the cute little loli, the sweet and pure young married woman, the cold and aloof CEO beauty, and all kinds of other beauties surrounded him.