Well, 'The Unholy' is purely fictional. It was crafted by the imagination of the writers and not inspired by any actual happenings. The story and its elements were made up for entertainment purposes.
In most cases, 'Unholy' is not rooted in real events. It's probably the product of the creator's imagination and creative process. There's no evidence suggesting it's based on actual happenings.
The cast list for " Ambush on All Sides " included Director Zhang Yimou, Takeshi Kaneshiro as Constable Jin, Andy Liu as Constable Liu, Zhang Ziyi as Little Sister, and Song Dandan as Madam.
The mastermind behind the ambush on Fan Xian in the valley was Chen Pingping. Chen Pingping had planned the ambush in the valley to prevent the Qing Emperor from suspecting Fan Xian. Although Fan Xian had survived and successfully defeated the mastermind, the information on who had ambushed Fan Xian was not clearly mentioned in the search results provided. Therefore, it was impossible to determine who it was.