Erandur

Erandur is a male Dunmer, found at the Windpeak Inn in Dawnstar, he is the the quest giver for Waking Nightmare.

Biography
Serving as a priest of Mara, Erandur fled the cult of Vaermina residing in Nightcaller Temple, after unleashing a sleep inducing miasma and sending several Orcish invaders and Vaerminian priests into a comatose state in the process. Renouncing his worship of the Daedric Prince in favor of Mara, he changed his name from Brother Casimer to Erandur.

Erandur was a member of the Bards' College before his affiliation with Vaermina was discovered.

Interactions
Speaking with the Jarl of Dawnstar, the Dragonborn learns of a fatal condition pervading the citizens of Dawnstar. Several fall asleep indefinitely while others complain of dreadful nightmares. Finding Erandur in the White Star Inn, the Dragonborn agrees to follow him to Nightcaller Temple and end the streak of nightmares. There, it is revealed that the Dragonborn must enter the memories of Erandur, using Vaermina's Torpor, an alchemical draught, which reveals Erandur as a former Vaermina cultist. Succeeding, Erandur and the Dragonborn proceed toward the altar of the temple, hoping to destroy the Skull of Corruption and end the nightmares occurring in Dawnstar. The two are attacked by Veren and Thorek, priests of Vaermina, who accuse Erandur of fleeing from the battle, and not falling into a paralytic sleep. Defeating them, the Dragonborn has the option to allow Erandur to perform a ritual and destroy the Skull of Corruption or take it for themselves. Before making the decision, Vaermina calls out to the Dragonborn, promising great power if he or she chooses to slay Erandur. Choosing to obey rewards them with the Skull of Corruption, while refusing opens Erandur as a follower.

Follower

 * Erandur dual-wields Flames spells, switching off to a Glass Mace (or at higher level, an Ebony Mace) when in melee range. He occasionally uses a bow to do battle from a distance.
 * Erandur wears simple robes and will not equip enchanted mage robes, even if the enchantments exceed the value of his default equipment. He will, however, equip Light Armor or Heavy Armor given to him, as well as any weaponry superior to his default Glass Mace.

Behind the scenes

 * While Erandur prefers to use Destruction spells and One-Handed weapons, these are his lowest combat skills. The "getavinfo" console command reveals that Conjuration is his highest skill (level 63), although he never casts Conjuration magic.
 * Choosing to banish the Skull of Corruption and let Erandur perform the ritual does make the Oblivion Walker achievement impossible to obtain, because as there are 16 Daedric artifacts, the Skeleton Key does not count towards the said achievement. It may be possible to get both artifacts from the Hircine quest, enabling the achievement, but it has not been verified that both will count towards the 15 required.