After Rebirth, the Female Knight Is Beautiful and Sassy

On the day the king ascended the throne, he pierced the heart of his most loyal knight with a sword. The legendary undefeated knight fell. However, she never figured out what went wrong until her death... She met the king when they were young, and she swore to protect him for the rest of her life, and she did. She watched him step by step from the most unpopular prince to the most powerful king in the world, and watched him marry a beautiful and virtuous queen. But why... "Alan, do you hate me that much?" Wendy asked with her last strength. She saw tears in the king's eyes, but didn't get any answer. Once reborn, she returned to the time when they knew each other, when... He was still a little prince.