Omal and the Knights of the Green Stone

Omal was a handsome prince (almost as handsome as me) who gathered elven heroes from across Reluria. They took the sigil of the green stone and affixed it to their cloaks. Then, with their weapons bathed in moonlight they faced the greatest darkness that Cadash had yet known - Naen the Crawling Chaos. Ah my friends, the adventures of Omal and his companions could fill many nights of song and story, but we have time for only one. So let me regale you with my favorite. It is a tale of rebellion, romance and radishes... yes, perhaps even the last radish.

- Taken from one of the tales of Nikitas Terzo 

Summary

Omal was an elven prince whose birth is considered the beginning of the end of the First Age of Cadash. Elves created by Yeno were already starting thier kingdoms and working with the First Folk to fight against the Chaos that was infecting the world. Kor's children were grateful for the aid and for a time the world seemed to right itself.
Then Naen the Crawling Chaos emerged from what is now called Ejo. First folk were weakened to this new creature's suggestions and powers. More and more of them turned from a life of peace and entered into a life of decadence and destruction. A new empire was created - the Jade Empire. There Naen was worshiped as a living god and his forces began to amass with a single goal, to wipe out the struggling federation of elves and First Folk on Reluria.
Omal rose in this time. He was brave, handsome and a wonderful orator. He gathered elven and First Folk companions to his side. It is said that both Yeno and Kor gave them blessings, and soon the heroes journeyed south to put a stop to the Jade Empire and it's dreams of conquest.
Omal's adventures are many and varied. He was unmatched in combat, his light silver blade moving at impossible speed. He used his charm and good looks to seduce a princess of the Jade Empire and turn her to his side. He faced the dreaded Naen itself on a number of occasions - but the creature had too many forms, and seemed unstoppable.
Eventually Omal and the Knights of the Green Stone broke the Jade Empire's grip on the south. Just how this was done is lost to time. Omal and his companions returned to Reluria to celebrate, but Naen was not about to let that happen.
It is said that somewhere in Reluria the beast Naen, weak but filled with impossible rage attacked the group. The prince and the abomination slew each other in a dark forest. The surviving Knights of the Green Stone put this prince to rest in a secret location and then returned to their kingdoms in the north. It is said that although Naen died that day, a seed of chaos was planted in one of the Knights at the same time. It would lead to the Massacre of the Green Wold and eventually to the The Chaos Elves.

Historical Basis

Like nearly everything from the end of the First Age, very little solid historical confirmation exists about Omal and his band. Even during the ancient Tyrian empire, Omal was considered a legendary figure - more based in fantasy than fact.
Elves with a strong background in history and the ancient world of the First Age do know a bit about Omal. But most of what is known is material passed down from bard to bard, or historian to historian. Some claim to have seen artifacts or documents mentioning the prince or his knights, but after the cataclysm all that was lost.
The stories persist. And even some cultural artifacts of the era remain. For example most elven bands of rangers or druidic protectors will wear a green stone upon their person. While the younger elves may not know why this is done, a few realize they are part of a older tradition.

Spread

Tales of Omal and his Knights are told infrequently in modern times. The bards that do know the tales also know that there are many versions and that they can vary wildly depending on who is telling them. 
First folk also tell tales of the Knights of the Green Stone, because several of the knights were First Folk heroes. Omal is mentioned as a peer in their versions of the stories, not the leader. In fact, the band always seemed to come together to decide what course of action to take. While Omal does take center stage at time (the seduction of the princess), there are plenty of other times other heroes stepped forward. 
First Folk point out that Omal's death didn't end the Knights. They continued for nearly one hundred years after that. They see that as proof that Omal wasn't a leader, but merely a colorful member of the band.

Variations & Mutation

Besides some of the cultural variations of the tales, there seems to be some confusion on other points.
The princess of the Jade Empire is a confusing figure. At times she appears to be an elf of some kind. Other times she is quite obviously a reptilian first folk (which ties closely to other elements of the Jade Empire). While nearly all the stories agree that Omal romanced and seduced her, many elves find it difficult to imagine a handsome elf prince sweet talking a lizard-folk female.
Naen the Crawling Chaos is a figure that is impossible to define. When it appears in stories it seems to have a new form. Sometimes male, sometimes female. It can appear to be an elf, other times a Sakasta and other times something altogether new. It did appear to be a serpent or dragon on a number of occasions. The defining feature seems to be its ability to corrupt and poison not just minds, but flesh as well. It is also pointed out in nearly all the stories that Naen is ancient, maybe even a fragment of Chaos that faced the Great Gods before life on Reluria started.