The Yinluo Sect certainly had no intention of fighting and dying for the Mulan People; they were merely there to harvest raw souls.
If the Tiannan Great Cultivators had been easy to deal with, Sect Master Fang would naturally have been happy to help the Mulan People stall them.
However, seeing that Li Feiyu possessed countless brilliant tricks and was far from easy to handle, he certainly had no intention of staying behind to fight to the death.
Chapter 298