Originally Posted by
Chronalis
Blood Elf Power is coming from the now cleansed Sunwell. Didn't you ever see the ending after defeating KJ, either in video or in game? They dunked M'uru into it, which being a Naruu, he's in harmony with the Sunwell. When a Naruu is close to death, it starts to turn darker. M'uru was an unusual case in that he was being somewhat controlled by the demon Entropius. When he died, he became a jet black shard and was put into the rest/rebirth state they enter at the end of a life.
By putting a naruu waiting on rebirth into the lightest place on earth will heal it, and in turn, help cleanse, and keep clean, the sunwell.
As such, we're embracing the power, rather than taking it by force. The old lore said we were stealing it by siphoning from a Naruu. This is true. When the Sunwell was cleansed, Lady Liadrin denounced all our loyalties to the "house of Kael'Thas", and pledged to help bring us back from the edge of destruction, and away from the magic addiction.
The green eyes you see are because we DID take power from demons at one point. Kael'thas appealed to Illidan, and he taught us how to siphon energy from demons. Take a look at the Patch 2.4 trailer. The old Mana Tap ability shows this "theory" in action.
We were actually the ones who taught Humans to wield magic... well, it was High Elves, but we're decendents to them.