How about when they give Alliance High Elves they make another neutral race. Medium Elves they will have PURPLE eyes they will be infused with raw arcane power giving them a purple glow. They will be from the nether from around bc a group of Blood Elves ventured into a portal along with the Etherals and they since have been traveling through time and space and branched off from the Etherals. Since they were in another part of the universe time worked differently for them so they have been a civilization for 10,000 years. They have their own culture and own new tactics and specialties. Being new to the planet of Azeroth they don't really have any preferences to factions and since there are two other races that look exactly like them some choose to venture with Horde and others choose Alliance.