Stories are still stories, so she doesn't believe in the legend about eternity. She always thought that no one would take her seriously, so she was cold-blooded and cold-hearted.
He thought he would never have a loved one in his life, but he fell into love by accident.
She is willing to put away her pride for him and wash her hands and make soup for him.
He is willing to trade a kingdom for her to live in peace for the rest of her life, and is willing to become the god of murder in the eyes of others for her.
He loves her and so does she.