suggestive of an elf in strangeness and otherworldliness; "thunderbolts quivered with elfin flares of heat lightning"; "the fey quality was there, the ability to see the moon at midday"- John Mason Brown
The Fey series of fantasy novels by Kristine Kathryn Rusch features a warlike elfin race of that name with powerful magick.
In the Dungeons & Dragons fantasy roleplaying game, Fey is a type of creature, or "creature type". Fey are usually humanoid in form, and are typified as having supernatural abilities and a connection to nature or to some other force or place.