Abandoned Princess' Magic Book

She was a proud, aloof, talented, and elegant princess who was unrivalled in the world. She was the princess of the Sky Rain Nation, loved and doted upon by thousands, and all the men were proud to be able to see her once.
Of course, she didn't care about them; he was a devilish, ruthless, dark, murderous man. He was a hero of the country who made his enemies tremble in fear, but he loved her deeply, tenderly, and with great care.
However, everything appeared to be on the surface. She loved him wholeheartedly; he had plotted and sought her home! In an instant, the country fell. From the princess to the imperial concubine to the lowly servant, she endured it and kept a low profile. She lived in a lowly position in his imperial harem just to avenge her country.
When they met again, he would be the cold-hearted emperor while she would be the unparalleled beauty who would bring chaos to the world …