https://wow.gamepedia.com/Ask_CDev#A...wers_-_Round_1
QUESTION: The Blood Knights of Silvermoon lack direction. None of them were seen in Northrend, and it is very unclear whether the Order still exists, or if it's been disbanded. It's also very unclear where the Blood Knights obtain their power, now. It used to be the Naaru but then... remnants of the naaru. Surely these remnants are all but tapped now. Do we obtain power from the Sunwell?
ANSWER: As of the end of the Burning Crusade expansion, blood elves who wield the Light do so through the power of the renewed Sunwell. It is a harmonious relationship, no longer one of discord caused by the blood elves' attempts to bend the Light to their will, which will likely have a positive effect on blood elf society in the long run. Look forward to updates that reflect this change in the Silvermoon and Blood Knight quests.
Mickey Neilsen, a senior writer in 2015, was asked on twitter (
https://twitter.com/MickyNeilson/sta...97143083659264)
QUESTION:Hi
. Like other Paladins, must Blood Knights have faith in the Light to use it, or CAN they just take it from the Sunwell?TY
ANSWER: The official answer I got was:
a mixture of willpower and faith in one's own ability.
BACK to Ask Cdev
QUESTION:Can you please explain how "light" works? The lore states that undead are physically incapable of using the light, much like the Broken, but then we have Forsaken players casting healing spells, and Sir Zeliek in Naxxramas using pseudo-paladin abilities.
ANSWER: Without spoiling too much, we can tell you that wielding the Light is a matter of
having willpower or faith in one's own ability to do it.
So, I can confirm that the manner in which the Blood Knights wield the light is the same as every other Paladin in Azeroth, the difference is that they can draw upon the Sunwell too. They are not stealing light from the Sunwell, the Sunwell is simply a vector which they call upon for aid. As Aurora proves, the Sunwell did not discriminate based on political opinion, all thalassian elves are connected to the well. All will, in time, be changed by the well. And there is no reason that the very few light wielding high elves who are still out there won't be able to use the Sunwell to aid them in the same way the Blood Elves can.