The Fair Folk are Essences that have passed through shinmaic principles that the five Graces embody.
By passing through Nirguna makes passing through the other four shinmas and possessing all four Virtues possible. It is Nirguna that makes realising the other four shinmas possible.
Pure dream stuff cannot exist in Creation so the Fair Folk must look like something from one of those dreams. The Fair Folk body is just an appearance and it has to expend Essence just to make it's appearance be believed by those in Creation since dreams only exist in people's minds. If no one continues to believe it, it would cease to exist.
Lunars can also manipulate dreams like the Fair Folk do.
Rakshas don't have 'bodies.' They just create the illusion of having one.
Assumption Charms are how the Fair Folk enter Creation. A Creation-born would need some sort of apposite in order to enter the Wyld.
Since their appearance is an illusion they have to spend Essence in order to maintain the lie of interacting with the physical world which as sentient dreams, emotions and desires they are not actually capable of doing. The more like their real selves they are in Creation the more difficult it is.
The more real their appearance is the less like their real selves they are, the easier it is for them to exist in Creation. Their appearances are not real things but only appearances conjured through glamour. The more powerful this work of deceptive glamour is, deceptive to the Fair Folk as well as to onlookers for to appear to have a form when you are a dream is self-deception, the less at odds they are with Creation.
