According to Esther's notes on her character floating around on Twitter here are some details about Yun Wei Shan :
1. Captured by Wufeng since young and seeks survival (so I was right she probably has known HYS for a long time)
2. Her face has an exhausted and worn-out look because of her long period of training at WuFeng
3. She has tracing skills and is skilled in martial arts
4. Personality-wise she is good at scheming and acting. But she is kind and can't bear to see people do evil things.
5. She doesn't level up because she can't bear to kill people, not because she doesn't have good ability
6. She is tired of a life full of bloodshed and wants to be free, bears everything patiently
7. Does not have a "love brain". Even the person she loves can't keep/tie her down. (Maybe for now but I feel like later, based on previews...this could change in some ways.)