Edited and reposted on my deviantArt account.
Don’t mind me, I’m just trying to work out the mechanics of how certain elements of magic work in some of my storylines.
Consider this a “first draft” of the idea.
Oddly enough, the reason I came up with this had little to do with figuring out how the magic worked, and much to do with deciding why some of my major characters might not be precisely human.
A long time ago, a distant and faded memory to even the oldest of realms, the worlds were separated by a powerful barrier.
Vast seas of pure magic flowed between one world and another, transcending time and space, and denying access to any who did not have the courage or the skill to cross them.
There were few, then, that knew there were other worlds to find.
The dragons, in their many shapes and kinds, were travelers by nature, and not unfamiliar with magic.
Then there were the mages, and the creatures they often summoned to act as familiars.
And there was one kitten who, it was believed, learned to cross these seas through sheer force of will.
And there were still other beings who knew the way.
There were also the Wandering Ones, bound to the magic as it was bound to them.
They were not vessels, but living embodiments of this magic. Their natures directed the flow of the magic: where it flowed, how strong it was, how best to use it. And how it was used changed that flow again and influenced their natures.
The Wandering Ones were believed to be human once (or what passed for human in a given world), but their relationship with the magic’s flow changed them. Some grew fur, or feather, or scales. Some possessed wings, while others had tails. Some learned to tame these changes, and others became wild things.
All of this was before the waters shattered.
Nobody truly knows what happened. All anyone knows is that life was once normal—each world with its own definition of “normal”—and then things were not.
The barrier between realms was shattered, and people found themselves thrust into unfamiliar territory, or hosting unexpected company from still other places.
And when the barrier shattered, the magic ceased to flow as it once had. Instead of flowing around and between the worlds, it flowed into them, merging with the water itself.
And everyone exposed to these shattered waters began to change.
First the creatures living in the seas. Then those on the shorelines, along the rivers and lakes. Finally the changes spread inland, away from the water itself. Even the desert dwellers were not unchanged.