On the final leg of the journey to Demon Slaying Spirit City, Lin Yi did not encounter many members of the Demon race. According to the records within the Tai Xuan Dao Palace, the number of Demons in the outskirts was quite low when they weren't engaging in attacks. The areas surrounding the expansion points of the Dark Abyss had the highest number of Demons.
Moreover, once it was sensed that someone intended to destroy the Abyss, a large number of Demons would appear to prevent its destruction. Similarly, upon detecting foreign beings within this region, an equal number and identical realm of Demons would emerge from the Dark Abyss.
Thus, the more Cultivators that entered this region and the higher their realms, the greater the number of Demons would be.
During a Demon siege, a massive amount of Demons would pour out of the Dark Abyss, fearlessly rushing towards the cities of the Human race or the Demon Tribe.