However, based on Nie Fan's recent performance and previous promises to him, Li Fei was absolutely capable of achieving this and would also help Nie Fan bring Chu Yaoyao over. The primary condition for all of this was waiting until after they had eradicated Qi Nian Hall.
Li Fei could see that because of Chu Yaoyao's past experiences, Nie Fan now hated Qi Nian Hall even more. Seeing the Longevity Pill later, Nie Fan would probably realize that Chu Yaoyao might not have known from the start about the ordeals her daughter would face. All this could have stemmed from Gongsun Mo's desire to conduct certain experiments.
As a healer, using living humans, his own patients, for experiments was an utter moral degradation and inhumane practice.