From Book Three of Kannes — Seles
Emperor Xteru made many enemies over the millennia. During his reign loyalties were tossed to and fro as he pitted one group against another, wholly annihilating some until he was no longer able to perceive friend from foe. It was a reality magnified during the time of Sammu the Illuminator, whose teachings were in direct contrast to the harsh ordinances imposed by the imperial caste system.
“War erupted and a great deal of knowledge was lost”
A top advisor known as Mokunar of Sippur, was a secret follower Sammu and he viewed Xteru as a preventative force opposing universal balance. After Xteru returned from a battle against a separatist sect of Sammu’s followers, Mokunar struck him down in a moment of weakness, like Guuerdur had been struck down so many years before. Unlike Guuerdur, Xteru lived, although his power was greatly diminished. The royal guard caught Mokunar trying to escape and imprisoned him for Xteru to execute once he had recovered.
But due to the passage of time and unknown to most all, Xteru’s injury resulted in a shattering of the barrier he once erected to imprison his ancient brothers and sisters. Slowly the elder Iru began to appear from the nothingness, plotting their revenge against the betrayer. War erupted and a great deal of knowledge was lost as the Sdu Empire was thrown into chaos.
Alliances were formed and many of the royals began to secede. Xteru rallied his armies and the ethereal forces he commanded, the children of that old life, known as Ozun and the profane Abrogation, and yet war raged on with unimaginable destruction until the Day of Ton, when it was broadcast across the empire that Xteru and his army had disappeared. Sdu loyalties were dissolved and in a short time the empire collapsed.
The Day of Ton is still observed to the present day, although it goes by many names, all seen entirely as a day of independence.