Sylphs are beings of wide-open spaces and the air. Sometimes they are depicted as cloud beings. Sylphs are responsible for the myths of "angels", the winged protectors of the Garden of Eden. Their attitudes embody the extremes of nature, mercurial and intense. Most of all, they defend the high peaks and wilderness mountains that are their home.
Sylphs are creatures of the air, and their great wings allow them to soar with the eagles. Sylphs can fly 25 yards + 5 x their dexterity per round. Sylphs are believed to be an offshoot branch of the sidhe, winged rulers of the Dreaming, controllers of the weather and the great birds of the mountains.
Sylphs are loners, content to soar the skies with the eagles. They care little for the machinations and politics of "ground folk", and they rarely interfere with changeling society. Like trolls, sylphs hold their word of honor to be inviolate, and once sworn to protect something, they will defend it to (or even past) their death.
Like the sidhe, sylphs are very regal in manner and bearing. Theirs is an ancient and proud legacy, and it is dying out. Fewer and fewer sylphs fly as the modern world creeps in. Most sylphs feel that this is the end of their race, that they will be the first of the kiths to slip into the Fimbulwinter. It is for this reason that they have come down from their mountains and rejoined changeling society in large numbers. If they are to die, then at least they will be remembered for the honor, glory and majesty that is inherent to their kind.
Appearance Sylphs resemble tall, lithe humans - with one exception. Sprouting from their backs are a pair of huge feathered wings. These wings are almost 2 body-lengths long, but fold up behind the sylph when they are on the ground. Their eyes are large and shaped like a hawk's, and their faces are sharp and angular.
Childlings sylphs are timid and flighty. They rarely associate with others, but when they do, they usually form bonds that last for life. They are called Cherubs by the rest of changeling society.
Wilder sylphs are intense and direct, like the birds of prey they resemble. They soar endlessly through the skies, looking for something to attract their interests and allow them to prove their worth.
Reference: Encyclopedia Britannica