Gao Buqin did not believe in this evil and used even more sophisticated methods.
His golding palm turned into a Yin-Yang Diagram as he tried to forcefully revert Yan Liling out of her current state, changing her from an intangible form to a tangible one.
Unfortunately for him, Yan Liling created that pill using Wang Wei's power of Nothingness. As such, its essence is not simply intangibility but the concept of nothingness.
Gao Buqin then changed tactics as his Weapon Body changed, taking the properties of a rare Time Artifact. Then, he attempted to revert Yan Liling to a few minutes prior when she was not in such a potent state.
His attempt failed as nothing can affect nothingness–not even time.
However, Gao Buqin currently had the mindset of a fool due to his desire to end this battle as his master ordered. As such, he did not believe he could not succeed.
He then chooses to attack Yan Liling's past self; by killing that version, he can eliminate the present version.
Alas, this method also failed. One of the properties of nothingness is its infiniteness, which transcends time. So, such a technique might have worked on past Wang Wei, who had little to no mastery of the Power of Nothingness.
But it was different for his current self.