Culling the Beast is a side quest in Skyrim: Dawnguard.
Culling the Beast is only available to the Vampire Lords faction.
Culling the Beast begins in Castle Volkihar
Culling the Beast is a quest given by Feran Sadri.
Kill the Master Vampire at (Random Location)
Go to the dungeon mentioned in your quest log, and kill the Master Vampire
Potion of Blood (3)