Shattering of Aaru
A civil war between the Ehoshim that happened so far in the past that it is little more than a vague myth to most species at the current time. The two factions in this war were the Nephulem and the Belephim. This resulted in the shattering of the Ehoshim homeworld, of Aaru - The First World into many pieces across many planes. The bigger pieces, known as "Aspects", became the 7 worlds of The Heptarchy. Smaller pieces became known as Shards of Aaru. The Ehoshim inhabitants were similarly split across these planes. So that an Ehoshim individual will exist on all 7 worlds/planes of The Heptarchy with the personality traits more associated the that plane/world more prominent. The non-Ehoshim inhabitants of Aaru were left broken and twisted on the world/plane of Archeron where they became known collectively as Ghulan. The billions of people of the worlds of the Khorai were also impacted hugely. Since all of Ehoshim technology and magic was derived from and powered by The Ilios, all this was destroyed or weakened as The Ilios was also shattered alongside Aaru. Even the Kyrioi, the Ehoshim who were not caught on Aaru during the Shattering, are much diminished in power.