Nocturnal Nocturnal ( in Daedric script , ) is the Daedric Prince whose sphere is the night and darkness . She is also known as the Night Mistress and " Lady Luck " . The Cyrodiil ic Thieves Guild leader , the Gray Fox , has the Gray Cowl of Nocturnal , which truly represents the sphere ' s darkness quality ; it permanently removes the wearer ' s specific identity from all history . Regardless , the Cyrodiil Thieves Guild venerates Nocturnal by ending talks with the saying " Shadow hide you . " The summoning date of Nocturnal is 3rd of Heartfire . Nocturnal and Azura have been referred to as sisters , though whether in the literal or the metaphorical sense is unknown . Appearance and personality . Physical descriptions of Nocturnal are difficult to come by , as she is usually described as being hidden by darkness and shadow . Depictions of the Daedric Princess usually take the form of a nondescript human woman , draped in a hooded cloak that hides most of her features and body . She is depicted with both arms outstretched , and a pair of Nightingales ( or similar bird ) perched on each wrist . Nocturnal claims to be an aspect of the void of Oblivion itself , and takes such titles as Mother of Night or Night Mistress . Her very nature is such that humans cannot understand her , as she is the embodiment of the unfathomable and enigmatic . Worshipers of Nocturnal consist primarily of those who operate in darkness and night , such as thieves and spies . However , Nocturnal ' s deception is not usually meant to be harmful or violent in the manner of Boethiah . Rather , the unknowable nature of Nocturnal is the core of her being , and serves no real ulterior purposes beyond being mysterious . Thus , while thieves may consider Nocturnal their patron , assassins will typically lean towards a more violent deity , such as Molag Bal or Mephala . Of Nocturnal , Karliah says she is , " like a scolding mother who pushes her child to do better , " meaning she is not fully considered evil , unlike most other Daedric Princes . Worship . Although Nocturnal has arguably one of the largest followings of all the Daedric Princes , she has no form of organized clergy . There are a few who call themselves priests of Nocturnal , though the Night Mistress does not herself seem to show them any particular favor . Indeed , Nocturnal seems to have no real interest in worship . A temple of Nocturnal does exist called the Twilight Sepulcher , located in Skyrim , though this was built around the portal known as the Ebonmere , the portal to Nocturnal ' s plane of Oblivion known as Evergloam . Supposedly , Nocturnal is the source of a thief ' s luck , which flows from the Ebonmere and plays a heavy role in the lives of any who use the shadows to do their work , though none know what price is paid in return . Nightingales . Though Nocturnal has no truly organized clergy , she has three mortal servants upon Nirn who are known as the Nightingales . The Nightingales serve Nocturnal directly , granted the power over shadow , subterfuge and strife in exchange for their service . Once a Nightingale enters into their contract with Nocturnal , they are bound for life and beyond to serve the Night Mistress in guarding the Twilight Sepulcher and in Nocturnal ' s realm Evergloam until Nocturnal feels the Nightingale ' s contract with her has been fulfilled . Witches . Like most Daedric Princes , Nocturnal has female , magic - using worshipers known as witch es . In " Purloined Shadows " , a coven dedicated to Nocturnal is seen worshipping her . Nocturnal seems to enjoy the praise they give her , smiling as they sang of her great mystery . Artifacts . Cowl of Nocturnal . The most famous feature of Nocturnal is the enchanted cowl she created . This headpiece possessed the ability to completely hide its wearer ' s identity from mortal knowledge , including magical forms of scrying and identification . The cowl ' s power was so great that people would be incapable of even remembering the name of whomever possessed the cowl , even while the cowl was not being worn . No one would be able to retain any long term memory of interacting with the cowl ' s wearer , and even removing the cowl in plain sight of others would not break its spell . The cowl was reportedly stolen by the head of the Thieves ' Guild ( Emer Dareloth ) during the Third Era , promptly removing any memory of the person in question from history . Henceforth , according to legend , the bearer of the cowl was known only as " Gray Fox " , though it was not commonly known that the cowl was responsible for his infamy . The cowl was also told stolen in a song called " Song of Hrormir . " Nocturnal was tricked by Hrormir in order to save his old companion Darfang . She traded Darfang ' s soul for the service ( by keeping his soul ) of Hrormir , so that he would assist her followers dividing the kingdom of Aelfendor , but in the end the kingdom was left intact while Nocturnal ' s followers were divided . And the Gray Cowl of Nocturnal was also taken by Hrormir . To get the cowl back , Nocturnal was forced to release Hrormir ' s soul and left with nothing to gain . Skeleton Key . The Skeleton Key was reportedly owned by a mortal for the first time by an obscured person named Arrovan . Many years later , the Eternal Champion during the Imperial Simulacrum found a map in a dungeon in Valenwood that pointed to the location of the Skeleton Key somewhere in Summerset Isle . Using the map , the Eternal Champion found and claimed the key . Then sometime in 3E 397 , the Hero of Azra ' s Crossing found the Skeleton Key in one of the chests in the Citadel of Broken Wing . Indeed , the artifact travels between heroes and locations , as the legend says , it would never be the property of one thief for too long . In Skyrim , the Skeleton Key was given a new level of importance and power . In the Thieves Guild story - line , the Dragonborn discovers that not only can the Key unlock physical barriers , but also metaphysical ones . As demonstrated by Mercer Frey in the Blindsighted quest , the Skeleton Key also unlocks human potential . Frey ' s theft of the Skeleton Key from the Twilight Sepulcher ' s Inner Sanctum in the Fourth Era is said to be the reason for the hard times that have fallen on the Guild in Skyrim , since the Ebonmere , the gate to Nocturnal ' s plane of Oblivion , was kept open by the Skeleton Key , allowing luck to grace the actions of thieves throughout Nirn . It also allows the owner to pick any lock without the Skeleton Key breaking . For the reasons aforementioned the Skeleton Key might very well be the most powerful , if underestimated , daedric artifact known . The ability to overcome any obstacle regardless of it being physical or otherwise by its user . Plainly seen as it has no trouble opening a doorway to a plane of Oblivion .