Reaper (Dawnguard)

The Reaper is a secret boss in The Elder Scrolls V: Dawnguard, located in the Reaper's Lair, which itself can be found in the Soul Cairn. To fight it, one must place at least three Reaper Gem Fragments on its altar to summon it. The Reaper itself is a giant, ghostly masked figure that wields an Iron Battleaxe and can spit slime like the Afflicted. When defeated it drops three empty Black soul gems, an Iron Battleaxe, and a Daedra Heart, suggesting that it is Daedric in nature. The Reaper is mentioned by some souls, even they don't know what he is.

Trivia

 * Some souls within the Soul Cairn may give reference to him by saying, for example, "Shh, he's watching us!"

Bugs

 * Using the spell Detect Dead will reveal all of the Reaper's minions inside the floor. By standing above one of these minions and attacking, the Reaper and his minions will rise and attack the player, at which point they can be fought and killed without placing or gathering any of the Reaper Gem Fragments. Another way, not requiring the Detect Dead spell, is by walking to the far side of the room from the door. You can see the ghostly smoke effect comming off of the reaper through the pile of bone he is standing in, about where his head would be, if you go right up to him and try to select him as if to initiate dialog, he will step forward and his minions will rise.