Winterskorn clan put to sleep.
The Winterskorn War was a conflict between titan-forged instigated by the fire giants Volkhan and Ignis after the titan-forged were exiled from Ulduar by Loken. They armed the Winterskorn clan of vrykul who attacked other titan-forged across the Storm Peaks, and caught the attention of Tyr when they attacked the earthen. Tyr asked the Dragon Aspects for aid, and the war ended with Ysera and Nozdormu putting the Winterskorn into a timeless sleep beneath northern Kalimdor.
The Tenuous Peace
For many ages after Loken's betrayal, the titan-forged who were exiled from Ulduar spread across northern Kalimdor. The lumbering giants gradually trickled into the mountains and seas around the region, disappearing from sight. The earthen tunneled into the deep places of the world, where they fought for dominance against a race of brutish and misshapen creatures known as troggs. Many of the vrykul remained aboveground, congregating into small clans. Some of these factions wandered the harsh northern landscape as nomads. Others established dwellings across the forested tundra of the region.
A tenuous peace existed between these groups of titan-forged, but it could not last. In time, malign forces moved to assert dominion over the lands once protected by the keepers. Among these forces were two of Loken's own creations, the brutish fire giants Volkhan and Ignis. Both saw the Storm Peaks surrounding Ulduar as a land ripe for conquest, however they were aware that they needed to 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.
The Winterskorn Invasion
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 Volkhan and Ignis 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.
Knowing that he and his allies could not defeat the Winterskorn alone, Tyr called on the five Dragon Aspects for help. The noble Aspects grew enraged upon seeing so many dead titan-forged. Their fury only deepened when they learned that proto-dragons had been enslaved. Without hesitation, the Aspects took wing and unleashed their powers on the Winterskorn's iron ranks.
Much as they had done in the fight against Galakrond, the aspects worked in unison to overwhelm and the vrykul army. Alexstrasza held the Winterskorn at bay with towering walls of enchanted fire. Malygos drained the magical essence that fueled the constructs and golems, rendering them useless. He also shattered the enchanted snares that bound the proto-dragons and set the beasts free. Neltharion raised mountains from the earth to corral and contain the vrykul and their giant masters. Lastly, Ysera and Nozdormu combined their powers to create a spell that would bring a decisive end to the conflict.
Ysera and Nozdormu enveloped the Winterskorn in a cloying mist that caused them the titan-forged to fall asleep. These incapacitated creatures were then locked away in tombs cities across northern Kalimdor. They would not know the peaceful slumber of the Emerald Dream. Rather, they would languish in a timeless, unconscious slumber for thousands upon thousands of years.
With the Winterskorn defeated, Keeper Tyr at long last turned his attention to Loken. So long as Ulduar remained sealed off and the titan-forged were divided, more conflicts would arise. Tyr grimly concluded that unless he took action against Loken, Azeroth would spiral into an abyss of war and chaos. Tyr and his allied would bid their time and hatch a daring plan to steal the Discs of Norgannon from Loken in the hopes that studying the recording within (which included Loken's actions) would allow them to beat fallen Keeper. They eventually were able to pull off a daring plan and acquire the Discs, though valiant Tyr would lose his life against Loken's agents sent to retrieve the discs.
In the meanwhile the slumbering Winterskorn would continue to be warped by the Curse of Flesh. When they eventually awoke, almost every one of them would discover they had degenerated into mortal creatures of flesh and blood.