Other Notable Sidequests
Although there are other side quests and plenty of radiant miscellaneous quests (a handful for both the Dawnguard and Vampires, found in their respective lairs), we’re outlining the ones that offer the most tangible and valuable rewards - or are just plain interesting.
Find Arvak’s Head and gain a spectral steed
You main run into Avark’s owner (he’s a soul) on the main path leading through the Soul Cairn. He’ll give you the quest to find Avark’s head. You don’t need to accept the quest first to find the head, however.
Avark’s head is on an altar just southwest of the massive floating tower atop which you find the archer Boneyard Keeper during the main questline. Once you have the skull, you can select the misc quest and look at where you need to go on the map. Return the skull to this location, and Avark will become yours. You can summon him at any time using the conjuration spell you now have.
Fight the Reaper
The Reaper is a (sort of) hidden boss that resides in the “Reaper’s Lair” in southeastern corner of the north half of the Soul Cairn. You’ll need to collect three Reaper Shards and place them in the receptacle in the center of the lair for the boss to appear. Reaper Shards can be found in the chests directly underneath the soul-sapping crystals all around the Soul Cairn.
Be warned that at the time of publication, this quest can be glitched. Even if you have the required number of shards, the game may not register this if you do not place them in the receptacle all at once.
Defeating the Reaper gets you three empty Black Soul Gems, one Daedra Heart, and one dual-handed Iron weapon (not enchanted). Not exactly enticing, especially considering the legwork that goes into finding the Reaper Shards.
Morven Stroud’s Shop
Just beyond the wall at the center of the Soul Cairn, to right, you’ll find Morven. For 25 Soul Husks (which can be found all around the Soul Cairn), you can get your choice of a sword, a battleaxe, light armor, heavy armor, or a spell tome. None are particularly special. They are random and match your current level in terms of value and enchantments. If you find enough husks you can completely buy him out; just know that he only has one of each item.
Learn the Drain Vitality Shout
Though you may already know a shout by this name, the one in the Dawnguard DLC is a separate shout and has a different effect. You’ll have to find each word the old-fashioned way.
Stamina: You’ll find this shout in the stadium-like room of Dimhollow Cavern. Nab it while you are escorting Serana out during the “Bloodline” quest.
Magicka: While traversing the Forgotten Vale (part of the main questline of Dawnguard), you’ll need to search out a duo of dragons that appear from beneath a large frozen lake. The word wall sticks out like a sore thumb; the challenge is taking on these two named dragons simultaneously.
Health: This word wall can be found at Arcwind Point (pictured), far west of Riften. To reach it, look for a path just east of the dragon’s lair Autonmnwatch Tower leading up the mountain. Although Arcwind Point was accessible before the Dawnguard DLC, there was no word wall present.
Learn the Summon Durnehviir shout
After defeating Durnehviir at the Boneyard in the Soul Cairn as part of the main questline, the dragon will be waiting for you at the exit. He’ll teach you this shout, which can be used to summon him. He asks you to head back to Tamriel and use this shout to summon him.
The first three times you summon him, he’ll teach you one word of a new shout. After he teaches you that shout, he’ll contribute to battle whenever you summon him.
Learn the Soul Tear shout
Once you have the ability to summon Durnehviir, do so in Tamriel three times and he’ll teach you this shout. Using the shout raises the dead and fills a soul gem.