After defeating the Queen Mek and killing the three Hell Priests, the momentum of the demons began to weaken. The group was momentarily bereft of any leads, but for Duanmu Huai... this wasn't a problem.
Was the Queen Mek captured in vain?
In fact, right after capturing the Queen Mek, Duanmu Huai tossed her directly to the Night Guards, and then issued an order.
"Squeeze everything out of her brain."
Technologies such as reading memories and probing the brain were possessed by the Imperial and the Night Guards, and the Mek Tribe had similar technology. In fact, the Mek Tribe had taught this technology to the Yajinians, but they never thought that the latter would use this technology to deal with themselves.