Hey there! Cool start. I have to say, I was liking the skirt based on the lore (desert fantasy makes me think of flowy clothing, similar to Journey).
More about the lore; are they more tribal/ceremonial like witch doctors/ shamans? If so, could be cool with some tattoos, jewelry, etc. You could already have this stuff in mind, just spit-balling here. It might conflict with your Art Noveau inspiration though.
Looking forward to the progress!