I’d imagine the seventh force is either something outside of all the realms we currently know of, or Azeroth herself.
Since we pretty much learned that what Firim, Jailer, and N’zoth talked about was the same thing.
So what can be so horrid that even the jailer and N’zoth wish to stop it?
I’ll post some stuff here.
First from Firim:
If the different forces compete with one another to claim it (Mortal plane), they might be driven by the unconscious knowledge of another outside force that seeks it as well.
The six forces that pointed toward a seventh, and yet denied it. For a long while I considered this seeming contradiction no more than another variable. An unknown waiting to be solved.
But the song of the oracle continued to reverberate in my consciousness. And as I allowed my focus to soften, my grip upon the tangible to loosen, the geometry took shape in my mind.
It was both six AND seven. The six were one, and the seventh the other.
Did they desire union? The song seemed to say otherwise. Both were, yet only one could be.
The melody shifted. I shuddered at the shape it took.
This was not a variable to be solved. It was a solution awaiting its opportunity.
The song must not be allowed to end.
Do the First Ones still sing it? Truly, I do not know. But if they do not…
If they do not…
Who will?
It is clear to me now that there must be a Zereth for each force of the cosmos, and within them, an inner sanctum akin to the Sepulcher.
And if that is true, then these sanctums must be connected on some fundamental level; a connection that the Jailer sought to exploit.
What he began in the Sepulcher was meant to cascade outward from one Zereth to the next, until all were dominated by his power. The heart of the Shadowlands acting as a doorway to the heart of each cosmic force in turn, one after another bound to his will.
But if his scheme was thwarted, then why is my mind so ill at ease?
Because I have seen how fragile the pattern is. How delicate the scales that keep the six forces in balance.
And if the Jailer, in his act of malevolence, left behind but the most imperceptible of cracks in that pattern, then I fear what is tiny now will only grow, until the balance itself is prone to be shattered by another force applying relentless pressure.
I pray that the First Ones anticipated such an eventuality. That they would leave measures in place to preserve their grand design.
Unless…
Unless their design was never meant to endure.
And that… that is the possibility that haunts me.
So Firim believes that there is some outside seventh force, but there could not be a six and seven forces, and apparently, the song/pattern that keeps our universe together is quite fragile.
Also worth to note that the symbol of the first ones is a serpent, which is found at all first ones structures like for example Korthia or Oribos etc.
Also the first ones have some kind of connection to Azeroth as we found first ones artifacts on Azeroth during shadowlands, and with the whole first ones waygates working for us etc.
Now throwback to the legion expansion we found two notes, talking about the end of all things. What I found interesting is that even the void scream out for the light that it used to hate in this doomsday scenario, and I’ll quote it here.
An Emerald Dawn.
An emerald sun dawns in the vault of the heavens, but casts no shadow. The world lifts her voice in terror, but only one can hear her cries. From the space that is everywhere and nowhere, the crooked serpent feasts on stars. It has no eyes to see, but it dreams of infinite endings and beginnings.
THE END OF ALL THINGS
The crooked serpent with no eyes is watching from the endless sky. Forked tongues flicker through the black pits in dead stars. The veil between dream and dreamer slides away like skin from bone. And even the darkness howls for the light it once despised.<The rest of the note is illegible, covered in strange glyphs and scribbles.>
Just saying, an awful amount of serpent symbol stuff, and we have a mysterious seventh force on our hands that’s supposedly super bad for our reality. And a mystery bad thing that’s coming for us. I think the mystery seventh force is the crooked serpent.