I saw this movie and, like many others, thought it would be interesting to see the story continue.
My idea is that when she kissed him goodbye, she transferred part of her life-force and memories to him. He patiently waits for the right moment to free her. Could be an eclipse, some special day where the Buddha’s influence is weakest and thus giving them the opportunity to set her free. Easily enlisting the aid of her other snake demon friend.
I am a little wanting of some information. If the young monk-turned-demon really is a demon, then why is he allowed to roam free? That needs to be explained. Perhaps it is because of this ‘lapse in judgement’ from the main monk that weakens the Buddha’s influence to hold the White Snake demon in the tower?
If only Siu-Tung Ching could read this and make this happen.