Yan Nanlai wanted to capitalize on the special properties of the Blood Soul Pacification Spell to free Yan Xinghe from the control of the Emperor of the Dead.
As the battle between the two worlds continued to heat up, Yan Nanlai's method could be considered as the most efficacious way to thwart the Emperor's plan.
The Emperor of the Dead was very much aware of this seemingly insidious threat and had been guarding against it.
Prior to this, the Nether Priest, wielding the Life and Death Book, along with the evil spirit of the Blood River Daoist was on the hunt for Yan Nanlai. They were looking to disrupt the ritual which Yan Nanlai was performing.
However, their plans were foiled when Liang Pan and Gu Jun both rushed over to protect Yan Nanlai and to fight for additional time for the ritual to be completed.
Ironically, it was the Emperor of the Dead's spiritual altar that was being breached by Yang Qing, Li Yuanfang, Gu Yuankai and the rest.