Throughout your travels in Skyrim, you may come across an extremely powerful undead creature called a Dragon Priest. These creatures are the remnants of an ancient group who worshiped the Dragons themselves as gods. In return the dragons granted these Dragon Priests with great power; today these Dragon Priests are coming back to life thanks to the return of Alduin.
There are eight named Dragon Priests lying wait inside of sarcophagus’ should you come across one, slaying it will allow you to loot and use said Dragon Priests namesake mask with special powers. Setting out to obtain all eight masks will be no easy feat as some of these Dragon Priests are only accessible by completing quests such as The World-Eater’s Eyrie, The Staff of Magnus, A Scroll for Anska, Evil in Waiting, Otar’s Mad Guardians, and Seige on the Dragon Cult.
Once you have obtained one of these Masks, you can then travel to Labyrinthian, if you fast traveled simply walk forward towards the South and up the stairs to locate the small round building with a Dragon Shrine. A decapitated skeleton is rested at the foot of the shrine with a note and a wooden mask. Pick up the mask and read the note; once you finish the note, put on the wooden mask and everything will fade to black. When the light returns, you will find yourself in the same room only in a different time when the altar was whole. There are now eight different busts each relating to a different Mask of the Dragon Priests.Skyrim Sidequest - Masks of the Dragon Priest,