Ignis the Furnace Master

Ignis the Furnace Master is a fire giant construct that was created by Loken. After his defeat in Ulduar, the titan keepers brought him back and now he is working again in Ulduar's furnace.

The Winterskorn War
Along with Volkhan, Ignis saw the Storm Peaks surrounding Ulduar as a land ripe for conquest, however, they were aware that they needed an army and to this end the fire giants turned towards the fierce Winterskorn clan of vrykul. After taking control of the clan by force the fire giants were quick to stroke the fires of their battle lust, while forging armor and weapons for the army designed to work against the other titan-forged.

However just as the new army was to embark on its great conquest, the Curse of Flesh struck. Seeing their forces succumb to it did not deter Ignis and Volkhan from their goal, but both were aware that they could no longer rely on the Winterskorn alone to achieve victory. To strengthen their army Volkhan and Ignis molded powerful molten golems and iron constructs of their own design. This massive Winterskorn army marched first against the good-natured earthen, storming their underground lairs. The earthen were utterly unprepared to face such an overwhelming and organized force. Entire caverns were massacred to the last living creature.

A small group of survivors escaped the onslaught and sought the help of Tyr, Archaedas, and Ironaya, who had thus far eluded Loken's wrath. Incensed by what they learned, Tyr and his companions immediately journeyed to the earthen's cavernous home to aid the beleaguered titan-forged. Tyr himself led the bravest of the earthen in skirmishes with the Winterskorn, while Archaedas and Ironaya constructed defenses to ward off future attacks. In time, the earthen and their allies drove back the Winterskorn.

Although their attempts to conquer the Storm Peaks failed, Volkhan and Ignis did not concede defeat. They returned to their blistering forges and created a new army - one even greater than before. Not satisfied with golems and constructs alone, Volkhan and Ignis crafted enchanted snares with which to enslave entire flights of proto-dragons. These creatures would serve not as mounts, but as beasts of war. The giants outfitted their winged servants with fiery weapons to strike terror into the hearts of the earthen. The Winterskorn's next brutal assault shattered the earthen's defenses and drove them from their refuge. The earthen scattered across the icy mountain passes, but they could not escape their foes. Vrykul and golems hunted the earthen on the ground, while proto-dragons assailed them from skies. Even Tyr, Archaedas, and Ironaya were forced to flee from the Winterskorn's fury.

However, Tyr was able to recruit the Dragon Aspects to his cause and they helped bring an end to the conflict by shattering the golems and constructs forged by Ignis and Volkhan, liberating the enslaved proto-dragons, and forcing the Winterskorn into a deep slumber.

Wrath of the Lich King
Ignis the Furnace Master is an optional boss encounter in Ulduar and can be found in the Colossal Forge. On orders from prime designate Loken, Ignis created both Kologarn and Razorscale.

Ignis is also a "memory" in the fight against Argent Confessor Paletress in the Trial of the Champion encounter of the Crusaders' Coliseum.

Bosstiary
''Like the other titan creations in Ulduar, Ignis now serves the Old God Yogg-Saron. This imposing fire giant toils over the Colossal Forge, creating the iron armies that will conquer Azeroth in Yogg-Saron's name.''

Adventure Guide
''Like the other titan-forged creations in Ulduar, Ignis now serves the twisted will of the Old God Yogg-Saron. This imposing fire giant toils over the Colossal Forge, creating the iron armies that will conquer Azeroth in Yogg-Saron's name.''

Battle for Azeroth
Ignis was brought back by the Keepers of Ulduar. Brann Bronzebeard and a dwarf adventurer approached him to help reforge the armor of Aegrim Bronzebeard.

Trivia

 * The name of this boss comes from the Latin word Ignis, meaning fire.
 * Some of the mechanics of the Ignis fight suggest that he is meant as a reference to the Greek god Hephaestus, god of the forge, blacksmithing, and fire. (Known as Vulcan to the Romans and Agni to the ancient Vedic peoples).
 * Ignis is voiced by J.B. Blanc.