Fey

The fey are non-mortal, sometimes-embodied collections of the spirits that inhabit the natural world and Shadow (aka ihimen or kami). These entities, when exposed to mortal influences and strong emotions, often conglomerate and take form, mimicking the acts and emotions that brought them forth. This leads to what appears to be obsessive behavior—a fey born of violence will rampage destructively or tempt others into such acts; a fey born of intense romantic feelings may become a serial seducer. The longer the fey exists without being destroyed or losing interest, however, the more this obsession develops into a full-on mimicry of mortal life in many aspects. They retain an interest in that one particular obsession, but it generally broadens and becomes less of a caricature. Make no mistake—fey are dangerous. They do not, except the strongest and oldest, understand death, as destroying a fey’s body simply shatters the collection and the ihimen separate without being harmed. The more humanoid and civilized a fey appears, the more powerful they are. [If you can't tell they're fey, that's a bad sign. Although the really powerful ones rarely care to hide it. --IB]

Fey cross over into Shadow naturally, existing on both sides of the veil almost simultaneously. Many of the most powerful make their homes there, rarely manifesting on the Mortal. Others have no home and flit about wherever their fancy (and obsession) take them.

Place-bound fey

Some fey, in contrast to this strongly mortal-centric view, are born from elemental influences or those of strong, highly-magical areas [especially trees, for some reason –IB]. These are place-bound fey, bound to a particular natural feature. They often form deep, almost symbiotic bonds with mortal creatures, trading vastly extended life and power to the mortal in exchange for a shared consciousness and being bound close to one location for the rest of their existence. These fey tend to be much less fickle, if bound to a mortal. The mortal provides an understanding of death, of change, and of the mortal world. Instead, these fey tend to be very fiercely protective of the natural feature they’re bound to.

Dryads

The dryad is a place-bound fey, usually bound to a grove of trees. They act as the protector and voice for those trees. They rarely take physical form unless provoked, and use their powers to keep the peace. Those whose trees have been violated by unnatural things (especially undead or demons) become very violent, however.

Emotion-bound fey

Some minor fey are obsessed with various emotions or states of being, to the point of being nearly one-dimensional. For example, the kipuliin are obsessed with pain, taking sadomasochism to the extremes. Satyrs are obsessive about intoxication.

Fey Animals

Some animals are exemplars of their type, with mystical properties as a result.

Hags

Hags once were regular mortals. But they became obsessed, consumed by an emotion. Even if it didn’t start out as a dark, violent emotion (such as hatred or envy), it usually warps into one soon enough. At some point, the Mother Tree, an eldritch, malevolent entity in the form of a colossal tree makes contact in their dreams and promises them eternal life and power to pursue their obsession, in exchange for their heart. The Tree plants its seed inside of them, and they become a hag. To stay alive, they have to continuously pursue their obsession, wallowing in that emotion at whatever cost. It’s rumored that if a hag reaches the pinnacle of its emotion and fulfills its obsession, the seed takes root and begins to grow into a Daughter Tree, a vile replica of a twisted mother.

Not all hags are women, but many are. The Tree favors them as its hosts for an unknown reason. Male hags tend to obsess about the most brutal things: pain, hatred, lust, and violence of all sorts. They’re less prone to obsession over envy, revenge, or sensuality. But hags of all genders and obsessions have been known to exist.