Xefhedle's Locket

 is a unique enchanted amulet.

Background
The amulet was enchanted by Molag Bal to contain Xefhedle, a Dremora who once served him but betrayed the Daedric Prince to pledge allegiance to Mehrunes Dagon. Molag Bal stole the Dremora's amulet and placed a curse upon it, trapping the traitor's soul, so that he'd serve everyone who comes to possess the locket. However, the Xefhedle's curse can spread to the wearer, corrupting him.

Acquisition
Xefhedle's Locket is worn by Acolyte Callonia.

Enchantment

 * Blood Binding: allows the wearer to summon Xefhedle via a conjuration spell added upon equipping the amulet. Unlike the common summoned creatures, Xefhedle can be used to carry one's excess items as well as be bound to a particular place, guarding it while the amulet is worn. If not guarding, Xefhedle's presence is only limited to a minute.

Trivia

 * The amulet's design features Mehrunes Dagon's face.