As Bright Mirror Peak true disciples, everyone present had seen An Jing's battle in Red Tower City.
They all knew that An Jing's abilities indeed far exceeded the normal limitations of a Martial Meridian, a genuine top-tier Heaven's Chosen that only appeared in significant eras.
They couldn't defeat him, they really couldn't.
As Martial Artists, it is important to be realistic and maintain the right attitude; after all, when fighting enemies in the future, the enemies won't be sentimental nor will they spare one's life just because one doesn't acknowledge one's weakness. Like mathematics, if you can't win in Martial Arts, you just can't win.
So they were very clear that if they could have a serious sparring session with An Jing, there was no doubt that it would improve their own prowess and uncover the deficiencies in their past cultivation.