Clavicus Vile's sphere is of wishes and eldritch deals. His dealing with Mundus (the mortal realm) are usually with individuals who wish to have something and, by summoning him, Clavicus Vile gives it to them. However, he is known to take back his deals at inopportune times (for the summoner, not Vile). Why he does this is unknown, though it is more than likely for amusement, as most of the Daedric Princes find mortal behavior humorous (much to the chagrin of mortals). 
The summoning date of Clavicus Vile is 1st of Morning Star. Clavicus Vile can also be summoned in his shrine, if the summoner offered 500 . Clavicus most often takes the form of a small, impish man with a pair of horns and has a nature fitting to both his name and appearance. He enjoys toying with mortals and finds them funny, but hates being bored and often does something to relieve the boredom.
N'Gasta and the Soulsnare
Circa 2E 896, Clavicus Vile is recorded dealing with N'Gasta, the Sload Necromancer of Stros M'Kai . N'Gasta created "Soulsnare", which gathered lost souls. The Daedric Prince Clavicus Vile granted N'Gasta favors with every soul sent to him. Cyrus the Redguard hero, in his desperate quest to find his sister, managed to destroy N'Gasta by using the Flask of Lillandril. Using the N'Gasta's Necromancy Book, he performed a ritual to transport himself to Clavicus Vile's realm in Oblivion. 
The detail of the ritual is as follows: in order to make a gate to Oblivion appear, Cyrus had to mix Orc's blood with Amber (jacinth - rising sun), mix the Unicorn's horn with Hist Sap (snow - grass), mix the Daedra's heart with Ectoplasm (night - mid-day sky) and then poured the mixtures on the symbol in the center of the N'Gasta's room, in that order. Then a gate appeared. Cyrus went through the gate and was taken to Clavicus Vile's realm. 
The sister and the flask
Then he dealt with Clavicus Vile, who was the holder of his sister's soul. Expecting to give back his sister's soul, Cyrus gave the Flask of Lillandril, but instead Clavicus Vile returned with a riddle. If Cyrus could answer it he might get back her sister's soul, but if he failed Cyrus' own soul would be Clavicus Vile's. Eventually, the wit of Cyrus served him well. The detail of the event can be read in The Story of Redguard.
Masque of Clavicus Vile
Circa 3E 430, the scholars recorded a Necromantic threat in Dagon Fel, Morrowind. A Necromancer by the name of Sorkvild the Raven terrorized the area. He somehow had acquired the Masque of Clavicus Vile after an unknown deal with Clavicus Vile. Sorkvild met his doom in the hand of an agent of the Imperial Legion, which is also the Nerevarine. 
About the masque, the "Tamrielic Artifacts" says:
Ever the vain one, Clavicus Vile made a masque suited to his own personality. The bearer of the masque is more likely to get a positive response from the people of Tamriel. The higher his personality, the larger the bonus. The best known story of the masque tells the tale of Avalea, a noblewoman of some renown. As a young girl, she was grossly disfigured by a spiteful servant. Avalea made a dark deal with Clavicus Vile and received the masque in return. Though the masque did not change her looks, suddenly she had the respect and admiration of everyone. A year and a day after her marriage to a well connected baron, Clavicus reclaimed his masque. Although pregnant with his child, Avalea was banished from the baron's household. Twenty one years and one day later, Avalea's daughter claimed her vengeance by slaying the baron. 
Hero of Daggerfall
The masque was owned by the Hero of Daggerfall as well, sometime around the year 3E 410. Obviously after dealing with Clavicus Vile. The Prince asked the hero to slay certain werewolf. After the deed was done, the hero was rewarded with the masque.
Feyfolken, the enchanted quill
A worth-checked fiction, written by Waughin Jarth, tells a story of a scribe and his enchanted quill, "Feyfolken." In fact the quill was a gift by Clavicus Vile. The quill gave a great benefit to the owner, but sooner or later the owner was doomed to always use the quill and could not be separated. When that finally happened, Clavicus Vile took the quill back from the owner and also his soul. This is the typical characteristic of Clavicus Vile's gifts.  
The Champion of Cyrodiil and the Umbra
Circa 3E 433, the Champion of Cyrodiil approached the Shrine of Clavicus Vile and managed to deal with the Prince. Clavicus Vile asked the champion to procure Umbra, an evil sword that has the power to capture the soul of its victim; however after long uses the sword usually consumes the wielder. The sword will possess the wielder. The sword bears characteristics of Clavicus Vile's artifacts.  The "Tamrielic Artifacts" says:
"The Umbra Sword was enchanted by the ancient witch Naenra Waerr, and its sole purpose was the entrapment of souls. Used in conjunction with a soul gem, the Sword allows the wielder the opportunity to imprison an enemy's soul in the gem. Naenra was executed for her evil creation, but not before she was able to hide the Sword. The Umbra Sword is very choosy when it comes to owners and therefore remains hidden until a worthy one is found."
The main purpose of Umbra is "entrapment of souls." Clavicus Vile said that the sword contains the soul of Umbra, a hero he had been dealing with sometime before and wanted to finish it. For procuring Umbra, Clavicus Vile offered his Masque to the champion.
The hound statue of Clavicus Vile jumped in to the champion's bag, and it introduced itself as Barbas. Furthermore, it said that it would be best if Clavicus Vile were not to receive the sword from the champion at all. Somehow returning the Umbra Sword to Clavicus Vile would be a mistake, likely to cause great ruin to Clavicus Vile's domain. Barbas also states that whenever Clavicus Vile deals with Umbra, nothing good ever comes of it.
From the "Manifesto Cyrodiil Vampyrum," it is noted that Clavicus Vile altered the Vampire blood of Cyrodiilic Vampires, made them be able to walk during daylight and most importantly able to deal among the common folks as another commoner - if they were well fed. This was actually a great gift for the Vampires, and quite possibly a turn against somebody wishing to fight them. Who Clavicus Vile tricked with this great service towards vampires is unknown. 
In Falkreath, the player may take the quest A Daedra's Best Friend. This leads the player to Barbas who then will lead the player to Clavicus Vile's temple in Haemar's Shame, a cave near Helgen. Before the statue of Clavicus can be reached, the player must kill all of the vampires and their thralls in the cave. Clavicus then thanks the player for killing the last of his remaining worshipers, as they had begged him to end their vampirism and he sees this as an acceptable solution. He then asks the player to find a special axe in Rimerock Burrow. When the player returns, Clavicus offers the axe to the player in exchange for killing Barbas. If the player does not, Clavicus will give his mask to the player, if the player does so Clavicus claims Barbas should have Picked a better friend. Barbas will become part of the statue the player chooses either option. 
- The Elder Scrolls II: Daggerfall Template:1st
- The Elder Scrolls Adventures: Redguard
- The Elder Scrolls III: Morrowind
- The Elder Scrolls IV: Oblivion
- The Elder Scrolls V: Skyrim
- ↑ The Book of Daedra
- ↑ The Elder Scrolls III: Morrowind - dialogue with Artisa Arelas
- ↑ Bible of the Deep Ones
- ↑ The Elder Scrolls Adventures: Redguard
- ↑ The Elder Scrolls III: Morrowind - dialogue with Gentleman Jim Stacey.
- ↑ 6.0 6.1 Famed Artifacts of Tamriel
- ↑ Feyfolken, Book II
- ↑ Feyfolken, Book III
- ↑ The Elder Scrolls IV: Oblivion
- ↑ Manifesto Cyrodiil Vampyrum
- ↑ The Elder Scrolls V: Skyrim
|Princes||Azura • Boethiah • Clavicus Vile • Hermaeus Mora • Hircine • Jyggalag • Malacath • Mehrunes Dagon|
Mephala • Meridia • Molag Bal • Namira • Nocturnal • Peryite • Sanguine • Sheogorath • Vaermina
|Related topics||Deities • Demiprince • Daedric Artifact • Daedric Shrines • Daedric Quests|