When the aliens from the Blue Fox Planet had invaded the Starry Crescent Land, everyone started to use the spell to communicate with each other. However, over the past month, the Blue Fox soldiers were able to construct a device that could intercept the contents of their direct audio. Therefore, using the spell to communicate was basically the equivalent of leaking information to the enemy!
After Mu Feng and his people suffered a few losses, they knew that something had come up and ordered the destruction of all the spells, which consequently broke the connection between them and anyone outside of the Starry Crescent Land. So, even after Gu Xijiu returned and created havoc for the enemy, Mu Feng and the people in Tianju Hall were unaware of her presence.
