The Workings of Magic

The main thing to keep in mind is that the magic nexi that Alabas relied on and that now power the Minds are not a natural part of the world. They were created by an ancient sage who wanted them to be used for the benefit of mankind, and then capitalized on by people who wanted them for personal gain, as these things go.

Naturally, magic creates networks and leylines that follow the paths made by their elements. In this way, currents carry water magic, winds carry air magic, root networks carry earth magic, and lava flows carry fire magic (The current theory is that the heat created by these flows is the relevant magical catalyst). These leylines shift as the land changes.

The nexi screw with that. The nexus is a disc-shaped artifact, that when given a magical pulse of energy (any energy) begins to spin, then to rotate around one axis, then two, then more and more and more until it resembles a sphere spinning in all directions. As it does this, the leylines in the area attract toward it as light passes by a black hole, away from their sources in the physical world. Once a leyline begins to feed directly into the point where a nexus resides, the relevant type of magic begins to build until it is violently released. This is the "pulse" of magic that, before it was harnessed by the ascension and upkeep of the Minds, began to change the elves, the kiria, and the aventi into their modern forms. With the regime of the Minds, this pulse is greatly limited (the Minds need much of it to stay conscious, plus controlling their cities on a daily basis means that they use the grand majority of the power collected daily by their nexi), only enough to predispose those already living there toward the type of magic the nexus projects.

The artifact orbiting around the moon is, as mentioned, an Alabasan invention. It works in a different way than the nexi, which take magic parasitically and project it out before they explode. The satellite takes in solar energy from Therinos' sun, then projects it out as magic, like a colored mirror changing the light that bounces off of it.