When someone dies in Ithelak, they go to Alronia (and thence to Cordime, and thence to the afterlife: their lives are divided into three portions). In Alronia, they are born into one of many different possible races (I am debating with myself about whether they have a choice about who to be born as or not).
One of the possible races is the fairy race.
A fairy is always of a kind associated with some element of nature. Flower fairies (you know: daisy, rose, orchid, pitcher plant, thorn bush, etc.), stone fairies (i.e. agate, gem, granite, etc.), wind fairies (north wind, local zephyr, etc.), etc. etc..
I am trying to work out their cobha though. They are like sylvans (or rather, the ones that are related to trees are), but I don't think they should die if their tree dies. They should be more like their houses, possibly. I also like George MacDonald's idea of their being able to change their size at will (read Phantestes and At the Back of North Wind).
So I am here to ask for ideas and questions.

A note: Alronia is governed by a cobha centered on emotion and heart. Ithelak is focused on power, ability, and strength. (Yeah, this sounds a bit like the HWCS, but trust me, Triterrus and my three worlds are quite dissimilar.) Its earth throbs with a musical heartbeat of epicness. People sing, and do not speak. The content of your heart manifests itself tangibly.