Phantoms are a race rather similar to elves in that I created them because I didn't want to use elves but wanted a race that could control elements. The first drafts of them were scary.
(not scary as in, they were scary, but scary as in how boring they were...) Being that I've mentioned them frequently, I decided I should once and for all reveal exactly who and what these creatures are. Phantoms are not ghosts or spirits anymore than any human you see walking down the street. They can marry humans, and their offspring can have up to all or down to none of the traits of their phantom parent. They do look quite different ( in what ways varies from type to type) from humans. Only one of the differences from humans are consistent - a phantom's eyes are never green or brown.
Here's the list of types, as copied from my document.
Fire Elemental Phantom: True name is Ignis Phantoms, but among some humans they are just the fire phantoms. Ignis will be used most of the time, though, because the MC’s are among phantoms. They find just plain ‘fire’ a derogatory term, though Ignis means fire. They’re not harmed by fire, unless it’s extremely hot (like, white flame, which is about 2300 degrees Fahrenheit) or very persistent (no dancing in campfires!). Their eyes are actually orange, and they’ve got dark red hair.
Water Element Phantom: Their name is the Nauta Phantoms, which would literally mean “Sailor Phantoms”. They look as if a piece of the sea detached and formed a people. Indeed, they always live by the sea or by lakes, for they can not bear to be away from the beauty of water for long. Their hair ranges in color from pale blue, nearly silver, to a rich aqua color (although not too vibrant). Leaders in their communities dye their hair bright blue and purple. Grey colored eyes are much more rare than blue. Their skin is quite pale.
Wind Element Phantom: The Aero Venti, occasionally called the wind riders. They can control wind very well, even cause small tornadoes (like, really small...) and handy gusts of wind, but their invisibility power is limited. They have silver hair, and grey eyes.
Dark/Non-Elemental Phantom: Tenebrae Phantoms or Noctis Phantoms. These are the most powerful phantoms, despite that they can control no element. Rather, they can blend into anything, even cause their shadow to disappear. This power is gained when they are about five. They can stay invisible for the longest time of any phantom. They are also one of the more rare phantom types. Because of their dark hair and pale skin, to those unfamiliar with phantom types, they are often confused with the Caliga phantoms.
Light/Non-Elemental Phantom: Their name is Aurora Phantoms, and they are most interesting. To hide, they bend light around themselves. (there are cloaks that do this, in modern times, I think...) They can also hide other things and people in the same way by doing this. They have light brown hair, and bright blue eyes. They tend also to have rounder faces.
Earth Element Phantom: They are called the Silvan Phantoms. It literally means “forest phantoms”. They are good at being quiet in the woods, hunting, etc, and are very powerful (invisible!) in the forest. But out of the trees their ability is greatly lessened. They are generally good with ranged weapons (arrows and stuff, I think those are called ranged weapons) which are the only somewhat practical type to use in a forest. They have brown hair and a wider build than the other types of phantoms.
Mist/Fog Element Phantom: Called the Caliga [ka-lee-gah] Phantoms, literally meaning “fog phantom”. Not only do they hate being called Mists, some humans call them Misties, or Misty, which is quite demeaning. Caliga are one of the most powerful groups of phantoms. Their invisibility powers aren’t as good as a Shadow’s by far, and their ability to cause fog to surround themselves is pretty useless, but most of them have unusual skill with weapons, particularly the katana and shuriken. Many don’t realise this, though, because such weapons are in short supply to the average Caliga. (Kai... is not average.) They have jet black hair and medium dark skin. Not a single one has blue eyes, all have grey. They have no region where they tend to live more than any place else, provided it is somewhat safe and secluded.
I have far more I could put here, but I do not wish to bore you, so I'll save it for later posts.
Hopefully you made it through all of that without too much skimming.
REALLY love them! Would you post more?
I love them, by the way. 
(I know, I should finish this one before thinking of another one, but it was a cool idea! Dragons and all that. 