So something I'm kind of wondering about, just as a tangential thought, but:
What happens if you try to use the Factorum Malleus on Not-A-God?
Like, what if Aeor had the opportunity to fire their doomsday weapon at a rival city? Vasselheim comes to mind if Aeor had actually killed off the gods. Especially given their mantra of "You can't trust the gods, only trust in Aeor" and the fact that Vasselheim is their biggest competition as a powerufl pre-Calamity city.
We have been told by the divine rundown that the Factorum does not kill to allow for usurpment of a divine Domain. It will just straight up erase the god from existence, like what the Matron did to her predecessor but without elevating a replacement into position. It will be like they never were, much in the same way that the disaster at Tengar destroyed the other... proto-gods, let's call them.
So what happens if such a weapon is not used on higher beings of great potential?
I mean, the obvious answer is that they get erased from existence too. Because if a god can't survive it, nothing less powerful is likely to have the correct resistance to survive such a force.
And this question then morphs into how to set a target for the Factorum. Does it lock-on to a single creature/entity? Do you need a piece of that entity to set it as the target? Is it a pulse-wave on the correct wavelength to utterly destroy a certain type of energy within a certain radius? Is it a death laser and you need to lure the target into the kill zone?
If it is a laser or destructive pulse-wave, you can certainly turn it against entire populations. Cities or certain types of creatures, depending. And even locking-on to one entity doesn't guarantee that more won't be taken out as collateral damage depending on how the Factorum Malleus hits its targets.
And of course the most important question in this hypothetical:
Can the Factorum Malleus be used against not-gods?
If the answer to that question is yes, everyone is fucked. Why? Because all it takes is hitting Exandria itself with that weapon to doom everyone on the planet, because the planet doesn't exist anymore.
Like, yeah, at the end of the day the gods were trying to take out the Factorum Malleus to save their own asses. But if we're being honest, they were saving everyone else too. Because Aeor would have become an even greater tyrant with a weapon like that under their control. And that's assuming they don't fuck it up and erase everyone and everything from existence with it.