Besides Bird Demons, there are also Wind Demons, Tree Demons, Cloud Demons, and other such things.
Wind Demons, as the name implies, are Specters that continuously emit strong currents of air wherever they pass. They are usually not formed from humans, but rather occur naturally when large amounts of Anomalous Energy accumulate in the wind. They can also be artificially generated.
They are typically used in the summer to cool down overheated regions.
Chapter 96