Firelords are a type of fire elemental that wear black armor.
Not to long ago in Azeroth, the firelord were somewhat like mercenaries. They were sitting in taverns and waiting to be hired by somebody. Firelords are described as vicious elites.
Firelord are encountered in the Firelands. They have the ability to create volcanoes due to their outstanding power. It seems the firelords have grown tired of sitting around taverns waiting to be hired, but instead have decided to join Ragnaros's forces. After Ragnaros joined Deathwing's side, both are trying to destroy the world. Many firelords can be seen and encountered in the Molten Front, the Firelands area Ragnaros is in, or the main Firelands region.