Before our modern age, there were rituals practiced throughout the world. There were similarities between these magics as well. Certain rules that appeared so frequently, they seemed to be embedded in us internally.
They are the law of similarity and the law of contagion.
In summary, the law of similarity means that like calls to like and things that are similar attract each other. It can also mean that the cause of something will elicit a similar effect.
Then, there is the law of contagion. This means things that have been in contact can still have an effect upon each other, even after being separated.
These two laws come into play in the mechanics of the Island Whispers magic. Rather unconsciously, I might add. I didn't learn about these two laws until this year.
The Magic of Island Whispers
Magic is woven into the very existence of every living thing. In essence, magic is energy and some have more of it than others.
- Vampires don't have a lot of energy; they have to steal it from others. Once they've drunk the blood (life/energy) of a creature, they can perform magic and their own natural abilities are heightened.
- Angels naturally are able to work magic, but can be affected if they use too much at once. They use "light magic" which requires drawing upon their own energy. If they don't have enough strength, then they won't be able to perform the magic.
- Demons also have innate wells of magic, but on a much lesser scale. The magic in their blood calls to fire, which is their element, and they can wield it if they've got the mental strength. Much of their magic relies on their mind/will.
- Merpeople also have innate magic, but it is rare. Magic is like a recessive gene and appears every so often in a family. Magic can be cultivated through practice, but still requires that spark to work it.
Keith is another story. He is a syran. A being literally made of energy which means that most everything is possible. Magic is inside him and is a part of him more so than any of the others. All of the others have specialized magic - magic that speaks to the core of them. Keith's core is magic, thus he can wield it in ways that aren't possible for the others.
Essentially, the law of similarity governs the magic of each creature - "like calls to like" - thus, magic of angels is like them: air, sunlight, weather, a bit of chaos, and sympathy. Likewise, I think you can see how the magic of the other three correlate with their base natures.
Sometimes these ancient ideas come to us naturally because they make sense. They follow the rules of the world and can be believed accordingly. It reminds me of Carl Jung's philosophy on archetypes and a collective unconscious. There are themes present in our minds that are also present in our history.