I Want to Die, But I Am Immortal - Chapter 29: Unforeseen Variable

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

Tong, a sinner who was suffering endless torment in hell because of his mistake he had done in his previous life, was giving other chance to redeem himself by the devil.

My name is Joo In-gong. The name that my parents gave me meant ‘protagonist’ of the world. Really?

As a reward for preventing the assassination of the current king, Rou Coral is rewarded with becoming and escort of the Royal Princess Reaina who the boy adores so much. Thus begins his new life of servitude under his beloved high-headed Princess full of happenings and happy little accidents. Surrounded with Busty Head Maid, young Loli Princess and a Childhood Friend Maid, for the boy knight today is yet another day of struggle in this womanly paradise!!