Maybe the Azure moon is where the EFB Fates lived
We know Hunger's cloak is associated with the Azure moon because it unlocked this pick.
[ ] [Azure Moon] - 7 Arete. That which reigns resplendent once in a blue aeon. The wearer gains access to his true [Soul Evocation], [Imprisoner], and high-grade talent in its use. Powerful as this may be, recall that the use of Soul Evocations requires extensive technical study which will be difficult to perform under the constraints of Hunger. However the potential benefits are enormous enough that it may be worth pursuing even at a mortal's pace.
And we know the Realm of Evening, or at least part of the Realm of Evening, has a moon. Or is at least influenced by a moon.
The lambent draping of the Evening Sky unfolds and billows in a dream-stoked wind; unbound by the lunar whim, become again the wavering noren to a place of wonder and grandeur unspeakable, the indigo terraces and night-traced valleys of Evening's Realm. Starshine like dewdrops gleams through clouds of pellucid haze: here, there is no strife, only rest, only joyous recumbence beyond the furthermost dreamings of men.
And we know that the Temple, which had a dimensional fracture to ???, was able to produce glowing runes whose light unlocked soul evocations.
The exact relationship between the Azure moon and the Realm of Evening isn't clear. Is the moon part of the realm of evening? Or is it merely close by and able to influence parts of evening? Hunger's initial cloak didn't have a moon...
From the jewel of his ring burst forth a cloak, wrapping up and around his arm to rest upon his shoulders. It was the stars and the evening sky, a texture like billowing clouds, the fall of its drape a velvet window into night.
But at the very least the Azure moon will be in the sky.
As for what the Azure moon actually is, my guess is that it's the same location as the Halls of the Lazulite from EFB.
In the Halls of the Lazulite
So far we've seen two links between EFB and Simple Transaction. The first are the rings, one of which was offered as a remittance and another we found at the Temple. And the second are the Liches, one of which was offered as a remittance and the second of which, Crowelenarch, was implied to be at the Temple writing intelligence reports. It's not clear what happened to Crowelenarch, if it died or fled or was on the other side of the dimensional fracture this whole time, but it's very strongly implied to be a lich. So there's lots of links between the worlds of EFB and Simple Transaction.
Lazulite is an Arabic word meaning 'heaven', making it a fitting name for the home of the gods. There are lots of mentions on google of Lazulite having the color of either azure-blue or sky-blue, meaning that calling a moon made of Lazulite the 'Azure moon' would make sense. We never learned much about where the Fates of EFB lived, other than that it was another dimension, and that it was called the "Halls of the Lazulite". So perhaps those halls were on the same Azure moon that exists in the Evening sky.
The Halls of the Lazulite is an odd name. The Lazulite Halls are a building made of Lazulite, but the Halls of the Lazulite sounds like a person, Lazulite, owned those halls. Or maybe that everyone within those halls are the Lazulite. Perhaps there was a person, maybe a companion of the Forebear, whose name was The Lazulite and who build the place? Or maybe it's just poetic language and I'm overthinking it.
Was the voyaging realm made from bits and pieces of the EFB world, and that's why bits and pieces like the rings and liches and moon survived? Did the Fates and other gods oversee multiple worlds from their lunar abode? Why did Prolessarch leave his world? No mention of Prolessarch time-traveling is mentioned, does the EFB world still exist as another realm we could potentially visit?
So many questions, so few answers. Point is, just seeing the Azure moon in the Evening sky isn't enough, I want to go there now.
523 words.