[...]
And so it was, when Ulric returned to the battlefield, he saw the rats feasting, and realised his great mistake. In their great consumption the rats had taken on a remnant of those foul Gods' power, and become like them: a new race, like the Humans and the Dwarfs, only made from pure Chaos. They, like all things of Chaos, would work forever to destroy Humanity and all he had built, and to one day bring about the victory the Chaos Gods had been denied. He saw too that the Daemon troops that had been routed had returned and carried away what was not eaten, and then had fled to the darkest corners of the world. They, too, these Beastmen, would watch and wait for their chance to reclaim the world from Men and Dwarfs. Ulric had saved the earth, but he had doomed the mortals who lived there to ever face the threat of a similar destruction.
Although it was too late, Ulric struck his hammer hard on the stony ground and brought forth a great flame with it. And with that flame he burnt all that foul offal that remained to ashes. Then he charged his brother Manann to drown the whole field with water so it could never more taint the land. The waters of the ocean poured over the field, and it became the Sea of Chaos.
Then Ulric turned to the fate of the Men. He taught them how to mould steel to make hammers and swords and axes, and taught them how to wield them. He taught them how to fight, and to hunt, and to kill. And lastly he taught them how to make fire and how to use it. All of this was to prepare them for their endless battle with the minions of Chaos. He taught them well, and gave them courage. He took charge over Mankind, and promised he would ever watch over them, for now their lives would know only battle. In return, the people of Ulric pledged to never suffer a Chaos-thing to live while they had breath in their bodies, and to ensure that every beast of Chaos that fell would be burned to ash, cleansed from this world by Ulric's Holy Fire. Thus, the taint of Chaos would never spread again. Ulric's mistake must never be repeated, and creatures like the Skaven must never again be born unto this world. And so we keep our pact forevermore. We strike without fear against the Ratmen, and the Beastmen, and all the creatures of Chaos, and raise the cleansing flame of Ulric to all the heavens above.