Vlanders is a faun with the ability to heal by removing negative energy or illness from living things.
When Mierna first meets him, he’s lost this ability. Instead, he is a puppet to a circus Ring Master, who uses him to pull out people’s energy. The energy is then stored within his horns for collection later on.
Vlanders is dubbed a Taker, those capable of harmful acts. Unwillingly, he has allowed the Ring Master control over him because if the Law Keepers of Fae discovered his flawed power, then he would be killed.