It had been some time since the Grand Preceptor fell into slumber, and although there were still four of his Earth Immortal Realm disciples—who were quite strong—the four of them simply were not the Grand Preceptor. They could suppress one area, yet they were incapable of dominating an entire dynasty like the Grand Preceptor could.
After the Grand Preceptor's slumber, the borders of the dynasty fell into chaos.
The Red Refinery Demonic Sect and the Sun and Moon Demon Sect were the first to invade the Guardian Immortal Imperial Dynasty, causing trouble.
Of course, their troublemaking was merely a probing action.
However, as the changes in the Heavenly Dao became increasingly apparent and more people fell into slumber, the Grand Preceptor's four disciples also succumbed one after another to slumber.