User blog comment:Sicknote45/The Elder Scrolls V: Dawnguard: Vampire Lord or Dawguard Defender/@comment-5220961-20120624082038/@comment-3524429-20120624204557

That would be perfectly reasonable. However, you actually go to the Dawnguard fortress first, then you can join the Volkihar. Also, in that E3 video, the guy was wearing DG armor and then turned into a vamp lord.