The biggest thing that stuck out for me reading Sullivan's letter to Deirdre was the history of Neithernor and where the Silver and the Storm fit into all of it. Here goes:
My research of Neithernor goes back to Anne of Brittany’s death and the eventual splitting of her court of artists’ secret guild into the paths of wool and silver. At some later point in our current history the path of wool became Monarch’s Mountain so that’s what I’ll call them going forward.
The Monarchs discovered a small but verdant place connected to our world through secret entrances, but wholly hidden from us.
Neithernor was not affected by whatever removed magiq from our world. That’s how the Monarchs learned that there was an alternate history of magiq.
This set of excerpts tells me that while the Path of Silver (and therefore it's Storm) had it's origin some time after magiq was hidden from the world, some time before Anne of Brittany - sometime before the early 1500's!
There was peace for an untold time. But then something unknown happened that pitted the Monarchs against the Silver. I don’t know whether it was a gradually building conflict or if there was a single catalyst, (or who was ultimately at fault) but it escalated into “The War of Neithernor.” Many were lost but MM drove the Silver out of the land and barred all entrance back.
The Silver scrounged for power here in the mundane world, trying to use everything they had to get back in. But they had been exiled.
While wild and forgotten, Neithernor is likely totally free of the influence of the Silver and their Storm.
Years later, The Council sent The Book of Briars to Monarch’s Mountain and the Silver scrambled to take it from them. They had grown strong in their own secret place here in the mundane, using what they learned from Neithernor and gathering artifacts and objects from the old time… They had also created The Storm. Once they realized the book was not for them, they sent the Storm, and in doing all but wiped away any memory the Monarchs had of Neithernor.
This is where I find his letter most interesting. Early on (before The Last Oracular Eye and May 31st) many of us had colluded Kemetic Solutions and the Storm. I did not think that was the case, but Sullivan's letter even broadens the scope of what we're facing. It puts way more players on the board than what I think we all originally thought was the case.
We found out (the hard way) that Kemetic Solutions was not part of the Storm. They were wiped out by the Silver and their Storm for trying to pierce the Veil by sacrificing adepts to an arcane apparatus. After that, I had assumed that The Storm was the operating militant arm of whatever had originally set magiq apart from our world. Now, with information from Sullivan's letter to Dierdre, I can no longer assume that is true.
What does this mean, practically? While the Silver and Storm are powerful, they aren't so powerful as to be the ones who initially took magiq from the world, and their motives seem to revolve around petty vengance more than anything. This makes facing them seem like a much less insurmountable goal.