Dark nights in Dubai
When someone becomes an archmage, they gather up the symbols of the things that were attracted to their Mystery Play and turn them into a Cintamani, which is Archmage-speak for “the symbol of ’I’m an archmage’”. This means that everything made by those symbols gets altered, which makes new archmages cry until they become numbed to the transhuman gnostic horror of their existence™. But it’s okay, because they’re now an archmage. They’re a archmage because the Supernal says they’re an archmage.
The Golden Road Ascension is when an Archmage then goes "so… If I were to be an Archmage back down below, and, say, convince the two Wings that they’re same order and that magic is alive, then return to the supernal, I’ll have attracted the symbols of the two orders and magic’s not-aliveness toward the symbol of “I’m totally an archmaster”. I can then use the same trick as in my Threshold to hammer them into shape. Back down below will conform, I’ll always have been right and if I do it enough times, maybe I can make a symbol of “The Mysterium (PS: I’m Ascended)” out of them all. This is a thing to keep in mind – archmages Ascend by using Imperial spells to change the world so that it fits their personal “paradigm”. If they do it right, then they fool the Supernal into accepting their design as part of the makeup of the Fallen World, and so they become the supernal symbol of themselves.
Ascended beings (like the Exarchs) don’t need Lustrums. They just are the symbols that are their Cintimani. But what good would it do them to be symbols people couldn’t understand? How would Tetrarchs navigate to them? How could they make a prison of the human experience if they’re outside the human Eperience?
Which is why the Iron Seal of Time is the supernal symbol of “only important people drive history”. Time, yes, but it’s Time in a very human “crushing your hopes” way.