The Maddening of the Orcs

A comet streaked across the sky in the middle of winter. To the proud orcs of the Northern Wastes who emerged from their huts in ornate sealskins and carved iron and bone weaponry, its blazing tail could be seen in the sky through the heavy snow. The comet hit the northernmost ice sheet in late autumn.
Many orcs perished in the initial impact and many more from the breakup of the northern ice sheet. Refugees flooded to southern tribes on yet unbroken ice. Despite the impending winter the southern tribes accepted the refugees for this is who the orcs were at this time, an honourable people willing to help out their kin in times of need.
As winter set in the tribes were underfed and restless, many ventured out onto the treacherous broken ice to the north to hunt. Few returned, and those that did did so empty handed. The seas were barren. Worse still the returning hunters were not the same, violent, restless and babbling of the things they saw in the ice and fog. This insanity soon spread, no orc could look into the snow without seeing a being of ice and hate standing there. None could look into the ice without seeing eyes staring back. Many orcs died chasing these phantom beings out into blizzards or down into the depths.
This insanity affected not only the orcs but, through their worship it changed their gods and in the violence that sprung out between them Gruumsh, god of destruction and war, came out on top. It's said that in the age of maddening Gruumsh pulled out one of his eyes to better see clearly and with his focused vision saw a path forwards. Gruumsh directed the orcs south, across the World's Edge Mountains and into the realms of civilisation, where the inhabitants were weak and their food, their homes, their lives were all for the orcs to take.

I asked the story teller, an elderly orcish woman named Tyla Gowen, when these events occurred and she was unable to say definitively, these stories had been passed down for generations and many details had been lost. The old orcs had no access to paper with which to record their stories and whilst some may have been carved into bone or painted on stone the orcs either left these behind in their migration or later destroyed them, the more modern brutish orcs having no need of them. The timelines do line up with that of the Cataclysm, with the first instances of orc raids on civilised lands being during the reconstruction period, this would also explain Gruumsh directing the orcs from afar rather than leading them as you may imagine Tempus or Bane doing.
I then asked her how it was that she came to be living in a small house in Wurtbad seemingly unaffected by the maddening of her people. She informed me that in fact some, like her, are born unmaddened, more in common with her ancestors than her modern kin. Though she does admit that she still battles with the call to violence from Gruumsh. These unmaddened orcs are it seems completely random, both of her parents were violent raiders and she was sure they would have killed her had they found out her desire to escape and yet there I sat, on a cushioned chair in a cosy living room being offered tea by a six and a half foot woman with tusks as long as my pinky.