Magic
This is just a suggestion on how to work with magic, and explaining how the different races are affected by it or use it.
A portion of this comes from the series "Vampire Diaries" if you don't like that series then my apologies.
Magic is produced naturally by the world. Certain areas of the world have higher concentrations of magic while others have less concentrated magic, and some may even have no magic around it at all.
Magic affects each race differently for the most part.
Humans: Do not have innate access to magical powers. They can not call upon the natural magic of their own accord, nor is their body affected by the naturally produced magic of the world. However they use magic in their own way still, powering their machinery. Usually using magic minerals that have concentrated magical power from the world as a power source for vehicles, weapons, and the like.
Weres: Are affected by the naturally produced magic of the world in a physical manner. The magic is was gives them their animal like appearance and thus what makes them a were.
Elves: Elves are capable of channeling magic to a very limited degree naturally. Usually being able to affect nature, greenery, the earth, and the air with magic, but only these things.
Dragons: Dragons are both affected by magic on a physical level and capable of channeling it to a limited degree. On the physical level it is what allows them to transfigure themselves, making themselves look more human than they normally are. Their level of channeling is limited to one form of elemental magic. (Fire, Water, Earth, Air, Lightning, Ice.) And is usually channeled through the physical motion of breathing powerful breaths of their given elemental classification. (Or) Dragons are otherworldly beings that came from a different plane of existence and thus are immortal and use magic that is unnatural to the world.
Mages: Mages are any being that is of their race that have an innate ability to harness magic in ways unlike what is normal to their race. This is directly channeling magic produced by the world through their bodies, or around them using what can sometimes be construed as mere thoughts or actions.
The Fae and The Fallen: Magic that The Fae and The Fallen use is not magic that comes from the natural world. It is in fact otherworldly, as if their magic comes from a different plane of existence. Thus their magics are usually not limited by what one may consider the natural laws, but are limited by the unnatural laws instead. If they were unable to access this magic, they would be unable to use magic as the natural world rejects immortality, and thus magic rejects those who are immortal.
Vampires: Unlike The Fallen, they do not have access to the otherworldly magic. Thus because to natural world rejects their immortality they are incapable of utilitizing the magic that is produced from the world. (Sort of from Vampire Diaries, in the series "Witches" are able to harness magic as magic is a natural product of the world. But vampires are unnatural immortal beings, and because of that they hunger for blood, as an attempt for the world to keep them from society, there is a certain plant that is their weakness because they lived around a lot of these flowers, and thus the world turned them against the newly made immortals, I'm not sure why the sun is a weakness of theirs...I think it was like the world didn't want them to be active in the daytime? And finally, if a witch were turned into a vampire the witch would lose all access to her magical capabilities, because she was no longer "natural". Obviously I only took the last part. XD)
