William had never heard of the Wild Hunt back in his day. In the past, the military forces in Ravenwood Forest were made up of tribal warriors from various tribes.
For example, the tribe with last names like Wolfspeak, Eagle Feather, and Viper. They treated the 'wilderness spirits' in the forest as their tribe's patron deities and worshipped them. They turned the souls of wild beasts into tattoos and engraved them on their bodies, using their bloodline to arouse those savage powers.
But the power proved difficult to control due to its violent and powerful nature. Typically, those tribal warriors would only be engraved with a kind of Great Spirit tattoo, unlike these Wild Hunts in front of him, who were covered in tattoos like a human body.