I’m kind of getting the impression that the Devourers are some manifestation of things being completely broken down and erased. Things consumed by the Void seem to still exist in some way as part of what consumes them (seen with Dimensius unleashing his devoured rivals during his raid fight), things broken down by the Fel produce more Fel, but what’s eaten by the Devourers seems to just be broken down to nothing by whatever animates them, which is why they’re never sated by anything they consume and single-minded consumption is what drives them.
Perhaps they represent the “true Death” that Sylvanas speaks of, and the Shadowlands exists because without them, there is no cycle back into Life and Death means the devouring and permanent end of evedy soul (and perhaps even more than just souls.) After all, the Jailer wasn’t sending all those souls to the Maw. They appeared to just automatically flow down there without an active Arbiter in place to redirect them elsewhere. Almost like maybe the oblivion of the Maw (before Torghast was built or Zovaal started dragging landmasses into it) is some vestige of the original, natural consequence of Death, and the Shadowlands were put in place to change that.
Whether by the Titans or the First Ones (still seems like something beyond the Titans to me, considering what a huge deal Reordering just one planet is for even them, let alone an entire infinite plane of existence), the Shadowlands were always made out to have been something constructed. But that doesn’t mean the way things worked before they existed was necessarily better. The Devourers might be the original, natural denizens of Death who existed to eat the souls of everything that died, and who were forced out to the margins of the In-Between by the creation of the Shadowlands. And perhaps Death-aligned entities like Mueh’zala, who hungers to feed on souls rather than shepherding them into the afterlife, might also be primordial and ancient enough to be connected to some original paradigm of Death being the “true end” of one’s existence altogether.
It could also fit into why the Void would fear Death. It wouldn’t fundamentally fear something as basic as the armies of the Kyrian, Venthyr, Maldraxxi, Night Fae, etc. After all, it invaded Bastion like it would any other place. But as shaped as it is by the pursuit of infinite possible outcomes, the Void would probably fear some underlying force by which Death means the end of all possibility. Which isn’t what the Shadowlands represent, but could be what Death would become without them in place.
(Incidentally, since aside from its use of runes as a medium, Domination doesn’t really “fit” into the general way that Maldraxxus works, which makes me wonder if maybe the aforementioned “true Death” is related to how the Primus created it, as stripping away one’s identity to control them could also arguably amount to reducing them to empty vessels and robbing them of their individual “possibilities.”)
Insofar as their presence in Midnight, on Naigtal Decimus states that the Domanaar have been enslaving and weaponizing them through the use of Shadowgraft, and the presence of Shadowgrafted Devourers in holding pens there indicates that the Hal’hadar have been doing the same. They originally seemed like mindless beasts, but the addition of the floating humanoid “controller”-types in Korthia created the implication that there’s some caste of intelligent Devourers who purposefully start summoning more of their kind into breached realms, from which could infer the possibility of a centralized purpose ultimately being behind them.
I kind of wonder if maybe Death unfettered by the Shadowlands might be the 7th force that the other six “face toward, yet deny.” Among the myriad immortal denizens of the cosmic realms, the one thing they all tend to fear is permanent death with no hope of rebirth, so rather than the Titans alone, it may be that agencies of all six cosmic forces conspired to create the Shadowlands in order to bind true Death so it wouldn’t just kill everything. Perhaps the balanced, cyclical relationships between them all that produced the Great Dark was artificially imposed because the alternative was Death being the final and irretrievable endpoint of all things.
The automa is Zereth Mortis isn’t really specific enough in her observation to make it clear whether she’s talking about Devourers in general having lisst their original purpose, or if she just means the ones in Zereth Mortis, since those in particular were destabilizing and behaving erratically due to having been corrupted by their consumption of the unique energies found there.
