Jergosh the Invoker has rejected the ideals of the orcs and practices the dark and demonic arts of the warlock. A leader of the Searing Blade Cultists, Jergosh dwells within Ragefire Chasm, concocting a scheme dangerous enough to draw the attention of Thrall himself. He's guarding the Blood Filled Orb, which is needed to summon Zelemar the Wrathful if you have the quest [23D] The Path of the Adept.
Jergosh is identical to the other Searing Blade Warlocks in Ragefire Chasm, except that he doesn’t have a Voidwalker pet, has a few more hitpoints, and he hits a bit harder. He will cast Immolate and Curse of Weakness throughout the fight, which are identical to the Warlock versions and equally strong. Immolate is a somewhat strong DoT spell, and Curse of Weakness will reduce the damage dealt by the target by 6.
Be wary of the other Searing Blade Cultists around him. It is best to clear the area around him until only Jergosh and his close followers are left. Once that happens, take down Jergosh, and eliminate the cultists around him. Be careful of the curses he will apply, and his spells, which do slightly higher damage.