The Cycle is an ongoing process in Vyn whose iterations are characterized by the end of a blossomed civilization due to The Cleansing. The Cycle is not a creation of the High Ones, but it is maintained by them. The number of iterations is unknown, as is its origin, but it is known that thousands or more civilizations have already fallen within The Cycle, as seen by The Black Guardian.
You want to know if what threatens you threatens other realities, too. And yes, it does. The Cycle is a logical consequence born from the right circumstances... and these are not limited to your branch.
According to the Veiled Woman, The Cycle happens in all the parallel realities. Due to this, the Cycle is inevitable.
In order to make sure that The Cycle continues, and, therefore, that new High Ones continue being created, the High Ones employ the same pattern, known to work, in every iteration, by indirectly influencing people into doing their work for them. They have perfected this, and every iteration is an almost perfect carbon-copy of the other, down to the phrases uttered by the Emissaries.
First come the Pioneers, the first civilization to populate Vyn within the iteration. Despite their greatness, this civilization always falls, usually in a grand catastrophe. After that come the False Deities (such as the Light-Born), who create a theocracy (such as Enderal) and thus begin The Age of Gods. This theocracy marks the apex of a civilization, and usually lasts longer than the pioneers. The end of The Age of Gods comes with the death of the False Deities, which plunges the world into chaos and civil wars.
Around that time, the Emperor (such as Grandmaster Tealor Arantheal) appears, an emissary that leads the theocracy and denies the death of their gods to the people, in order to prevent chaos in their own country. The Emperor learns about The Cycle and The Cleansing, and intends to stop them. That's when the Prophet appears (such as The Prophet), someone with incredible powers that aids the Emperor into getting a beacon and its Black Stones. This leads to the creation of another emissary, whose name is never mentioned, that opposes the Emperor and fanatically wages war on religion (such as Taranor Coarek).
Backed by traitors inside the Emperor's own realm, the warmonger pressures the Emperor and Prophet into venturing to gather a Numinos, only for them to fail. The Emperor, for fear of failure, decides to light the beacon without a core, to cause an explosion that will destroy the warmonger. Unbeknown to the Emperor, they have just initiated what they sought to stop from the very beginning: The Cleansing.
The pattern, as experienced by the Pyrians, has been seen in the Echo of the Future by The Prophet.