MTL - Super Craftsman - Chapter 961 Surprise to be silly (below)

The story of a returnee who lived in the world of martial arts for 20 years and plays games instead of hunting monsters.Summary:[TS] Martial Arts Returnee’s Game Broadcast follows a martial artist who, after returning to modern society and undergoing a gender transformation, becomes a game streamer. The story mixes martial arts with gaming and live-streaming elements in a contemporary fantasy setting.

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

One day I got a younger sister.Only I know her true identity.