Here's a few villains for Changeling. It isn't a solid list, and it's probably not all of them, but it's what I've thought up.
Banshee: a metahuman villain, she has precognitive abilities and a scream that has more explosive force than dynamite. She went insane after foreseeing her own death, and went on a rampage that ended when Changeling put an arrow through her chest. Rumor has it that she's not entirely dead, but there isn't much evidence to support that.
Puca: Metahuman crime lord that uses shapeshifting powers and terror tactics to force families and businesses into providing him a share of their profits. Known to appear before victims as a demonic black horse.
Iron Man: A normal human and the brother of Banshee, he built a suit of iron and an iron sword in hopes of avenging his sister's death. He has attempted to take Caleb's life multiple times, and has gotten closer to finishing the job each time. He does not like being confused with the fictional billionaire of the same name.
Traca Hulder: a metahuman woman with super strength, she turned to villainy after discovering her husband had commuted adultery, and killed him, his lover, and anyone who got in her way. She's now in the business of ending anyone else that's less than loyal.
Herla, the Wild Huntsman: a vigilante demon hunter, Herla has superhuman strength and durability, the ability to telepathically control animals, and is a master archer. Due to being a fairy, Changeling has become one of the Huntsman's targets.
Tylwyth Teg: a Fay being responsible for numerous kidnappings of human children and their replacement with changelings, Caleb desires to bring him down to prevent infants from meeting the same fate as the original Suburu baby. His powers are similar to Caleb's, but his illusionary magic is far more powerful.
