After Gui Zhen left, Fang Zhiyao contacted him using a Sound Transmitting Device. Fang Zhiyao had said at the time that she could control Ding Fan, and promised that if Gui Zhen would lend a helping hand to the Upper Xuan Sect, she would be willing to use her own body as the price.
From the start, Fang Zhiyao had already calculated the matter of Wind Valley.
Wind Valley has always been the Upper Xuan Sect's harshest punishment for Sect Disciples, and for centuries, no one has walked out of there alive. It is said that hundreds of years ago, the Upper Xuan Sect had a stunningly decisive individual whose cultivation was rumored to be close to Profound Level.
Even such an awesome existence eventually perished in Wind Valley without ever leaving. So in Fang Zhiyao's view, there was absolutely no possibility for Ding Fan to come out again after entering.