Re: Opinions: A 'Hero' Stealing Their Gear.....????
Heck, there's the whole concept of the Wild Hunt and the Unseelie Court as well.
Another possible villain could be Arawn, Celtic god of the Underworld (used in the Prydain Chronicles by Lloyd Alexander).
The following are all mentioned in Brian Froud & Alan Lee's "Faeries" book in having some sort of malicious bent.
Hags (British Isles)
Jack-in-Irons (Yorkshire)
Leanan-Sidhe (Isle of Man, Ireland blood-sucking vampire who is also the muse of poets. "Those inspired by her live brilliant, though short, lives.")
Aughisky (Ireland water-horse related to the Kelpie of Scotland. "If the Aughisky is ridden inland, the rider is quite safe, but the slightest smell or sight of sea water will spell death to the rider...")
Nuckelavee (Scotland, water-faerie)
Jenny Greenteeth & Peg Powler (water hags)