Upon hearing Lu Chen's reminder, the restless hearts of the Great Emperors calmed down slightly.
What their Heavenly Emperor said was correct; the Heavenly Demons of the Shenyue Dynasty were very powerful, with quite a number of Emperor-level Heavenly Demons, perhaps not fewer than those of the Daxia Dynasty.
Of course, the power of the Heavenly Demons was one aspect, but another was that the Heavenly Demons of the Shenyue Dynasty were different from those they've encountered before, who only knew how to devour humans. Most Heavenly Demons of the Shenyue Dynasty were transformed cultivators, smarter than ordinary Heavenly Demons and knowledgeable in human strategies.
So even if their power had a suppressive effect on the Heavenly Demons, those demons would certainly think of other methods to reduce this suppression, like setting up traps or formations.