It Started With a Kidnapped Pig...
The goddess Mystra has had many incarnations, and she is the deity who manages the Weave, the source of all magic. Anybody casting any type of spell must tap into or access the Weave in some way. Because the Weave is a part of Mystra (or she is a part of it) the times when Mystra has been killed, almost always as part of some scheme of an evil deity, all magic across the Forgotten Realms has gone awry – last time it resulted in the spellplague which had catastrophic effects on some people and creatures as well as some areas of the land.
Mystra’s greatest enemies are Shar, who created the Shadow Weave in response to Selûne’s creation of Mystra and the birth of the Weave, and Cyric, who was a mortal along with Mystra and Kelemvor (with whom Mystra had a cold friendship). She was served directly by the Lesser Power Azuth (who was killed during the Spellplague), and indirectly by demipowers Savras and Velsharoon. Mystra also had powerful mortal servants in her Chosen including Elminster, Khelben Arunsun and the Seven Sisters.
Order of the Starry Quill
The Starry Quill is an order of Mystran bards who often work as information gatherers and rumormongers for the church or spend part of their time in designated libraries unearthing magical knowledge and then preserving it for posterity.
Order of the Shooting Star
The Church of Mystra sponsors an order of rangers, known as the Order of the Shooting Star. These rangers receive their spells from Mystra. They serve as long-range scouts and spies for the church and also deal with magical threats that threaten the natural order of things, such as unloosed tanar’ri and baatezu and creatures born of irresponsible wizardly experimentation.
Knights of Mystic Fire
The Church of Mystra sponsors a knightly order of paladins, the Knights of the Mystic Fire, who are granted their spells by Mystra. They often accompany members of the clergy on quests to locate lost hoards of ancient magic and also form the cadre from which the leadership for the small groups of armed forces who guard Mystra’s larger temples and workshops is drawn.