Mystra
The Mother of all Magic, was a greater deity and the second incarnation of the goddess of magic after her predecessor Mystryl sacrificed herself to protect the Weave from Karsus’s Folly.Mystra was destroyed by Helm when she defied the will of Ao the overgod and attempted to leave the Prime Material Plane during the Time of Troubles.16 At the conclusion of the Godswar, Ao offered the position of Goddess of Magic to the wizard Midnight, who reluctantly accepted and took Mystra’s name in order to smooth the transition after so much chaos.
“I am Mystra. I am the Lady of Might and the Mistress of Magic! I am Power Incarnate! Wherever magic is worked, there am I – from the cold poles of Toril to its hottest jungles, whatever the hand or claw or will that works the sorcery! Behold me and fear me! Yet behold me and love me–as all who deal with me in honesty do. This world is my domain. I am magic, mightiest among all those men worship. I am the One True Spell at the heart of all spells. There is no other.”
— The Mother of all Magic to young Elminster Aumar