Shar , the Mistress of the Night, is the goddess of darkness, and the caverns of Faerun, as well as a neutral evil greater deity. Counterpart to her twin Selûne, she presides over caverns, darkness, dungeons, forgetfulness, loss, night, secrets, and the Underdark. Among her array of twisted powers is the ability to see everything that lies or happens in the dark. Shar's symbol is a black disk with a deep purple border. Her divine realm is the Palace of Loss in the Plane of Shadow, and her domains are Cavern, Darkness, Evil, and Knowledge. She is also the creator of the Shadow Weave, meant as a counterpart and to foil the Weave, controlled by Mystra, the goddess of magic.
The clergy of Shar is a secretive organization that pursues subversive tactics rather than direct confrontation with its rivals. In addition to her clerics, Shar maintains an elite order of sorcerer monks who can tap Shar's Shadow Weave. Among her worshipers are the Shadovar (the citizens of Thultanthar, a floating city which is home to the survivors of ancient Netheril who fled into the shadow plane before Karsus's Folly). Shar holds power over all who use the Shadow Weave.
Shar is the dark twin of Selûne. She has battled her sister since shortly after their creation. Their primordial feud has resulted in the creation of many other deities. Rather than overtly confronting other deities, Shar seeks to gain power by subverting mortal worshipers to her faith.