I Pledge My Kingdom to Win the Rest of Your Life

The first time he saw her, she was small in stature, clad in armor, with stubborn eyes and a bloodthirstiness that rivaled any man's. She forcefully claimed a place in his heart... Though they stood on opposing sides, in the end, that could not withstand his ever-growing possessiveness. So he spent years plotting to claim the throne, offering her an empire as his betrothal gift in exchange for the rest of her life, so they could grow old together.