According to many sources, Vampyres were to be implemented in the Myth series just like the Dirigibles and the Skrael. While the myth world does include Skrael and Griffons--it is quite possible that Vampyres exist in the lore as well--especially with the amount of bats flying around the Ermine and the Watcher's arm. How they were conjured and if they had any will of their own is a mystery.