The Four Aspects of Chaos

"The very world turns against us!" the elves cried to Yeno. "Why does your creation destroy your people?"
Yeno whispered in a voice full of sadness, "My brother created Cadash from the elements. But those elements were already corrupted by Chaos. I used knowledge and magic to hold back much. Now I see that Chaos learns from my power, and turns it against you."
"Can you not help us?" The elves cried out. "We burn, we drown, we suffocate and we are buried."
Yeno scowled, "Chaos will fall to my power. Even now, Kor and I are preparing for a renewed battle."

Summary

Chaos is unknowable and unrelenting. While there are many symbols for this eternal enemy, most often mortals are faced with aspects of chaos. The Chaos Elves are the most well known of these, but there were many other forms. The most ancient were the ones that attempted to wrest control from Kor and The Great Wyrms. These were known only as The Four.
Each of the four was an element infused with chaos' power, maliciousness and tenacity. Kor found himself battling the very water, air, fire and earth around him. His people suffered and it was only through the intervention of Yeno that The Four were defeated.
But Yeno and Kor were disturbed, because The Four could not be destroyed. Chaos infused all the elements used to make Cadash. Instead Yeno had to bind them as best she could. Over the aeons one or more would break the binding and start corrupting Cadash again. But Yeno's power grew over time as well and she was always able to guide heroes to find them and bind them again.
But the consort of Yeno, Irev was a master of divination. Irev predicted that an age of Chaos would come, and it would be known because all of The Four would be free upon Cadash at the same time. The ancient enemy of Yeno's people would cripple them. The children of Cadash would suffer unto the very end of the world. There was hope, for ancient knowledge is not lost, only hidden. If the children of the gods work together, they will find that ancient knowledge, and cause one of The Four to be bound again - and stop Chaos for a time.
"Always for a time... not forever?" Yeno would ask. "No beloved," Irev would say. "For Chaos is within the hearts of all who know of it."

Historical Basis

Evidence of The Four aspects is rare. Most histories focus on the physical minions of Chaos and it's worshipers. When The Four are mentioned at all, it is usually as being the source of power for one of the more fearsome minions.
There are some ancient geographical features that are supposedly created by The Four, either at their birth, or at their binding. A volcano in northern Reluria was supposedly the birth place of the Fire Aspect. While it is said that the curse laid upon the The Sea of Dread may have come from the fact that the Water Aspect was inprisoned under it. Most historians don't consider that proof, but merely storytelling added to strange or foreboding geography later.

Spread

Most tales of The Four are tied directly to powerful Chaos Elves. For example it is believed that Leshanna, the eldest of the Three Daughters of Chaos had great powers of wind and storm magic, even binding one of the Great Wyrms to her cause. Some believed that the Air Aspect of Chaos granted her power. 
There are splinter groups of elves and First Folk that do have myths relating to The Four in their most primal and powerful forms, during the first battle against Kor and the Wyrms. They see The Four as being closer to the actual power of Chaos, and therefore a more dangerous threat. They keep the prophecy of Irev close, watching for omens of when the The Four will be abroad again.

Variations & Mutation

The Four have taken many forms over the aeons. They have also infused themselves into mortals, turning them into formidable foes. It is said that the eldest of Wyrms may have seen the original aspects during the war of the First Age. But no one has seen an ancient wyrm in hundreds of years.
The heroes of The Dread have encountered names that ring true with the ancient aspects of four: Naen and Axlos. But are these the names of actual aspects, or names for minions to those aspects?

Cultural Reception

The Four are rarely spoken of in most cultures. If they are, they are just another tool of Chaos, and added to a tale to give it more excitement. The Chaos Elves are the preferred antagonists.