Inspired by settings like Star Wars where magic divides into a calm rational meditative Light and a wild passionate destructive Dark, the world of Aetherline has three types of magic: Red for fire and darkness and passion and violence, Green for life and light and intuition and healing, Blue for wind and water and structure and intellect.
Also, the universe is structured around an ever-expanding invisible fractal of Aetherlines, where each node of the fractal holds a speck of dust that eventually grows into a planet, then splits apart as its sub-nodes grow large enough to hold entire planets on their own.
There are thousands of planets, each with its own unique local conditions. Culture, biology, and lingering influence from the ruins of ancient civilizations can all affect how magic is accessed and conceptualized in a particular area. Sapient species range from human through humanoid to entirely alien, with most falling somewhere in the middle.