This character is also from the Chinese TV serial "The Disguiser".
Her name is Manli Yu. She holds an unrequited love to her battle companion who see her as the trustable friend.
This scene is when they get ambushed. The brave girl decided to sacrifice herself to save her companion.
She once said, "I never fear about death. What I fear is that I will never see you after I die".
This is her last gaze on her deepest love.
She is sad because she will never see him. She is happy because she knows he can live.
I try to convey this mixed emotion.