"I curse ye gods, now and until the day the last snows melt. For ye have forsaken my people, and have brought upon ye-selves the wrath of a hundred thousand dead men. Ye have watched as death washed over our lands, and ye did nothing. Now, I, Ymiron, become death itself, and on this hour, I tear ye heart out, and feast upon it."

- An alleged quote from King Ymiron God-Killer, before murdering Valarn, the Divine God of Courage.

Ymiron God-Killer, also known as the Lord of the Jyruuk, The Jailor of Sithis, the Herald of the Scourge, and The Fallen King of the North was a warlord-king of an ancient human civilization known as the Jyruuk. These ancient, giant human species resided in the icy, frozen wasteland known as Northgar in Velous. This is where Ymiron ruled over his people as king.

However their new home was not a utopia, as terrible circumstances arose sometime during Ymiron's reign. Seeing his people die quickly from disease and famine, the King Ymiron prayed day and night to the Divines for reprieve, but they said nothing in return, and offered no signs. Losing hope, Ymiron pleaded to the Dark God Sithis for help. Sithis initially didn't care at all about the paltry lives of mortals, but he eventually saw the potential in making this King a pawn. The Death God agreed, only if the King waged war against the Divines. Almost without a second thought, King Ymiron agreed, and was granted powers over death and shadow by the Death God himself. With these powers, he created armies of undead, resurrecting a huge number of his fallen people, deforming them into dark creatures of mindless hate and bloodlust. This army of undead came to be known as the Scourge. King Ymiron then supposedly shouted up at the heavens and performed all manners of rites that mocked the Divine Gods.

According to legend, one Divine, Valarn the God of Courage, was so offended by this, he descended to the world of the mortals and appeared as a great warrior before the Cursed King. Valarn challenged Ymiron, and the two battled ferociously. According to all legends that recall this tale, Ymiron slew the Divine's avatar and devoured his heart. This earned the King the title "God-Killer". So grief-stricken and furious, Anurel, the God of Rulership, cursed the Jyruuk and sent down an apocalyptic ice storm that raged over Northgar for ten years. This eventually froze King Ymiron, his people, and his kingdom, where they remained trapped in the ice for millennia.

However, close to two thousand years later, after the Mythic Dawn War, as Sithis was defeated alongside Aku, the Death God sent a surge of his dark power across the world, where it landed in Northgar and resurrected the Dead-King Ymiron, his undead champion from thousands of years before. Ymiron's awakening brought back the Scourge to life, now stronger than ever. The Fallen King immediately began his quest again to destroy the Gods once again, and he ended up helping to start the Black Diamond War, where a fragment of the ancient Sargeras, an evil being from before Creation itself, was released unto Existence.

Since the Black Diamond War's conclusion, King Ymiron has not been heard from again, and his icy kingdom of Northgar is strangely silent.