Lords of the Emerald Flame

The Lords of the Emerald Flame are an incredibly powerful enemy of the worgen. They do battle with the worgen on their native homeworld, and Velinde Starsong got to know of this ferocious war through her use of the Scythe of Elune. Apparently, the struggle against the Lords of the Emerald Flame does not go too well, as the worgen found their enemy to be an unflinching one indeed.


 * "Holding the Scythe in my hands, I received a vision of chaos. Wolf-men... the worgen... battled an incredible enemy. The worgen fought savagely, as fit their primitive race, but their enemy was unflinching: the Lords of the Emerald Flame."

It is revealed that the Lords of the Emerald Flame are satyrs. The Lords of the Emerald Flame gathered together most of the demons left in behind in Azeroth after the Great Sundering to form an army. This remnant of the Burning Legion made the War of the Satyr against the night elves in Ashenvale for revenge. The Worgen/Pack Form was used against the demon army, expressly against Malfurion Stormrage's command. Tyrande Whisperwind supported Malfurion's decision, stating from her knowledge that the form was liable to have the druids fighting each other as much as the demons.

Xalan the Feared was likely their leader.

Speculation
The Emerald Flame may be a reference to fel magic.