The Greatest Warrior of All Time Returns - Chapter 181

The story revolves around Charles Karino, a Levaamu Empire mercenary aerial pilot who mans the twin seater reconnaissance seaplane Santa Cruz. One day, he receives a preposterous assignment: to fly solo over 12,000 kilometers of enemy waters to protect a girl named Fana del Moral. Fana happens to be the next in line to the empire’s throne and a girl possessing beauty “equal to 5,000 beams of light.”

This is a standalone book. There’s another series under the name “To Aru Hikuushi e no Koiuta” (Love Song for a Certain Pilot) set in the same world, but in a completely different place and with different characters.

– Ulrezaj @ Mazui

Adapted to anime as “The Princess and the Pilot”

It was a hasty, arranged marriage.And on their wedding night, he ran away.He lived for ten years under a false name, becoming one of the 7 Great Masters of the Continent, but returned home when he heard news of his father’s passing.There, he found his wife, whom he thought had already left, whom he had only seen once before.She was still as beautiful as the first time he saw her.

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

The best way to declare war on a spy as an ordinary person is to become a spy as well.As a spy, if you want to go to war with a powerful espionage organization, join an equally powerful espionage organization.If you are unable to join any powerful espionage organization, then establish your own espionage organization and fight until destruction or victory.This is the war of spies, telling the story of how a group of ordinary people achieved extraordinary success.