Thomas's Forgotten Realms
The Dark Maiden
Eilistraee is the daughter of Corellon Larethian and Araushnee the Weaver (who later took the name of Lolth). She is a minor elven goddess and the sister of Vhaeraun. She is the drow goddess of song, dance, swordwork, hunting, moonlight, goodness, and beauty.
Eilistraee foresaw that the dark elves would need a beacon of good within their reach and allowed herself to be exiled with her people (dark elves) after very nearly slaying her own father with a misplaced arrow. Eilistraee swore never to use ranged weaponry again.
During her exile, the Dark Maiden wandered Toril. For centuries, she fought Vhaeraun, thwarting his efforts to gain influence over all the dark elves of the south. Despite many lost battles and setbacks, Eilistraee kept fighting to bring her hope to the drow and lead them back to their rightful place in the light.
In the Year of Wild Magic (1372 DR), the goddess Lolth went into a state of hibernation. Durign this time Eilistraee chose one of her new converts, Halisstra Melarn, to wield the artifact known as the Crescent Blade to kill Lolth before her awakening (in 1373 DR). Halisstra went on a mission to the Demonweb Pits, However, after being defeated at the hand of Quenthel Baenre, Halisstra ultimately decided to betray Eilistraee and The Crescent Blade was left broken, lying in the Demonweb Pits.
Eilistraee sought to recover the lost Crescent Blade; to that purpose, Cavatina Xarann, a Darksong Knight serving the Dark Dancer, went on a mission into the Demonweb Pits, where the sword was seen last. She recovered it almost intact and used it to kill the demigod Selvetarm in the Demonweb Pits.
On the same date Vhaeraun managed to infiltrate Eilistraee’s realm and attempted to assassinate her. Eilistraee emerged from the attempt alive but changed: she became a deity known as “the Masked Lady”, holding both the Dark Maiden’s and the Masked Lord’s portfolios and causing both their followers to cooperate, albeit uneasily.
In Flamerule of the Year of the Lost Keep, 1379 DR, the Masked Lady, while inhabiting the body of Qilué Veladorn, was killed by Halisstra Melarn using the Crescent Blade.
Eilistraee managed to return to life during the event known as the Second Sundering in Flamerule, 1489 DR. She and her brother were separate entities again, but after the time spent as the Masked Lady, they reached a reciprocal understanding, and the enmity between them was no more. Both deities have personally let their return be known, manifesting through their avatars to their followers, who enthusiastically are spreading the word.
Since then Eilistraee has been seen dancing and speaking to mortals in many places, especially along the Sword Coast. The citizens of Waterdeep witnessed the Dark Dancer, as she danced in the moonlight, near the walls of the city, up the road to Amphail. This has led many moondancers to the City of Splendors, with the goal of creating a shrine to their goddess within its walls.