Azura

"Azura is the Anticipation of Sotha Sil, but female to his male. Azura was the ancestor who taught the Chimer how to be different from the Altmer. Her teachings are sometimes attributed to Boethiah. In the stories, Azura is often encountered more as a communal progenitor of the race as a whole rather than as an individual ancestor. She is associated with Dusk and Dawn, and is sometimes called the Mother Soul. Azura's Star, also called the Twilight Star, appears briefly at dawn and dusk low on the horizon below the constellation of the Steed. Azura is associated with mystery and magic, fate and prophecy."
―Anonymous

Azura is the Daedric Prince of Dusk and Dawn, the magic between Day and Night, also given titles such as Mother of the Rose and Queen of the Night Sky. Her sphere is the period of transition and change, as seen in the constant twilight of her realm of Oblivion, Moonshadow.
Nocturnal has been referred to as her sister, though it is unknown if this is in the literal or metaphorical sense.

She is known to be one of the more merciful and benevolent Lords, though her wrath is swift and painful when brought about. She oversees the Daedric Realm of Moonshadow, a beautiful world of blurred colors streaming together, cities of silver, and air like perfume. The ones who visit this realm are mostly of either the Dunmer of Morrowind or the Khajiit of Elsweyr as both revere Azura, though in different respects. Azura can be summoned on the 21st of First Seed, or during the times of dawn or dusk at her shrine in Cyrodiil.