Does Mystra only have control over the magic of the Toril planet/Realmspace, or does she have control over ALL magic across the spheres and planes?
Does Mystra only have control over the magic of the Toril planet/Realmspace, or does she have control over ALL magic across the spheres and planes?
Eberron’s magic doesn’t come from Mystra at all. The biggest theory comes from (according to the blog of the setting creator) the Ring of Siberys, a giant golden ring of dragonshards that surrounds the planet. But Mystra doesn’t exist in Eberron at all.
Of course, Eberron is (according to the 5e book Rising From The Last War) sealed off from the rest of the D&D multiverse, so they operate by different rules by its very nature.