She is the legitimate daughter who was abandoned by her family and was forced to marry the remnant king who was shunned by everyone due to an imperial edict.
Everyone laughed at her for seeking her own death and waited to see her end miserably.
Unexpectedly, on the wedding night, King Can's eyes were deep and he pushed her against the corner:
"Princess, are you okay?"
She was shocked to realize that the seemingly sickly prince in front of her was not only neither disabled nor mute, he also doted on her, protected her and abused her, and had power over the government.
From then on, the legitimate daughter counterattacked and was favored by the prince alone. The whole world gave in to her.