Back then, Yang Zhenshan was able to save Lin Daoyuan and Yue E for two reasons. Firstly, because it was just the two of them, Yang Zhenshan decided to take a chance, treating a dead horse as if it were alive.
Secondly, Zhang Mo at that time still wanted the two to submit, so he did not deal them a fatal blow but merely sealed their Divine Souls and Sea of Consciousness. Thus, Yang Zhenshan was able to use the Seven Treasures Soul Suppressing Tower to protect their Divine Souls and detonate the Restrictions in their Sea of Consciousness.
However, the situation now is clearly different. The Unpredictable Ghost Sect apparently desires a compliant army of Ghost Soldiers. Although An Wusheng and Yu Yuan haven't completely erased the Divine Souls of these demon beasts, they have already worn them down to an extremely weak state.
Even if Yang Zhenshan can protect the Divine Souls of these demon beasts now, it will be very difficult for them to regain control of their bodies.
