An Eredar military order originially formed by Melchamas the Relinquished whilst he was corrupted and under the influence of demonology.
The Flamewrath are currently ruled by Zasalathar The Mad, Melchamas' son and a Broken One. They operate on Draenor as a secretive movement that seeks to kill any Demons, Draenei or any other opposition to their claim to 'rightful' rule of the planet.
The order was originally formed from the Argun Arcane Guard as a successor to the order to protect Eredar interests on Argus. With Argus destroyed, Melchamas reformed the guard under the Flamewrath, charging it with a duty to ensure Eredar interest remains paramount within the Legion and also renewed the order's magic, replacing their sorcery with demonlogy.
The Flamewrath partook in much Draenei slaying as well as any Eredar whom defied the legion. Trouble brooded in the mind of Melchamas however as he realised that the Legion were going to destroy the lands they visited and not install a seat of power for the Eredar.
Melchamas disbanded from the legion, earning the eternal emnity of Kil'Jaeden. He followed the Legion's plan to pursue the Draenei on their new homeworld: Draenor, but to instead kill the Draenei there and make Draenor a seat of Eredar power.
A battle ensued and the Flamewrath were defeated by the Legion as the Draenei fled. The Eredar in the Flamewrath had become demons over time, and thus they were banished by Legion warlocks. Melchamas was subdued during the battle and taken aboard the Draenei's dimensional ship.
The Legion rounded up the Eredar they banished and killed some, whilst torturing others for information about Melchamas. They tried to get his son and successor: Zasalathar to give them information but he didn't know, he eventually used his cunning to evade his captors and fled into Zangarmarsh. He used his demonolgoy magic to summon what Flamewrath survivors he could and re-orgnaised the order. Over the torture period the Flamewrath Eredar had been subject to cruel shadow magic, and most died, those that survived to be teleported by Zasalathar devolved into Broken Ones.
The Flamewrath are currently ruled by Zasalathar and consist of former members of corrupted Broken and Lost Ones. The order uses demonic magic to hunt down and kill Draenei and Demons that have come to Draenor, and are trying to build the seat of power they originally intended for the Eredar.