So I finished the vampire side of Dawnguard and recently found out there are quests to get rings/amulets that augment the vampire lord. How do I even go about getting these quests? I've looked them up in the wiki and I talk the NPC's that are supposed to give me this quest, but they just give me some unrelated quest. Do I just keep doing quests until Rings of Blood Magic pops up from them or what?