Fey is a natural addition to any deck that runs Blasphemous Covenant and Favor of the Moon. Every time you use Favor of the Moon on a skill test, you gain bonus of +3/+4 (or a +5/+7, if you're committing two copies of Fey) and a resource. And Fey returns to hand even if you fail somehow.
Since you're a probably seeker playing Deep Knowledge, it's almost trivial to always keep a Favor of the Moon in play; by the time you've depleted a Favor, you'd probably have the other one in hand from all your draw. It's the most reliable way to handle The King in Yellow yet and an easy inclusion in any Luke/Gloria/Daisy deploying the cursed spell suite. If you're Amanda Sharpe, you can return Fey to your hand to put it under for a second time. This effect is also amazing in the City of Archives.
Outside of such a combo, Fey is rarely worth the 1xp it takes to purchase the card.