It's important to make the distinction between Illidan's army (the Illidari) and the Burning Legion. They aren't just fighting you, they're fighting each other as well.
The Illidari are some demons and any naga, fel orcs, and blood elves (except the blood elves in the Sunwell dungeon and raid, those are Legion). Burning Legion are demons and the mortals in the Shadow Council.
Usually, Legion demons will be at camps with those green and black machines. Illidari demons will tend to name-drop Illidan, or wear the tabard, or have "Illidari" in their name.
12/09/2012 03:31 PMThat not only cleared up alot but it also answered questions about how the lich king came to be. So this Kil'Jaeden guy is the commander of the burning legion and then created the lich king to control what the scourge do?
Posted by Chozan
You're right that Kil'jaeden created the Lich King, but he's not... quite
the commander of the Legion. He's the acting leader for now, but the ruler of the Burning Legion is Sargeras. Kil'jaeden is normally Sargeras' right-hand man, just Sargeras has been gone for quite some time.