The decision tree is complex, but the questions threaded through it are simple. They have to be; communications aside from YES, NO, UNCERTAIN, and MU, which is a very infrequently used "The premise of your question is in error" answer, are much costlier. (n.b.: Irori successfully wove MU within commune, in a way that didn't noticeably increase intervention burden beyond the standard cost of Communing, shortly after His ascension. The absence of it as a standard answer was offensive to His sensibilities.)
Her Church would not be doing this if they believed it unnecessary. Therefore, something either very good or very bad is happening, and it is happening quickly.
There are a few hotspots that are worth checking nigh-immediately, and only one of them bears the characteristic signature of one of Her paladins praying for a miracle - though, as almost ever, not from her.
If She had the capacity to be faintly amused by the way Her paladin is politely avoiding taking up Her time more than once, She would. It doesn't work like that; there are always shards of Her attention upon Her paladins, to power the spells they requested.
Still. Even as the Commune's linkage is being forged, She can gather information She anticipates will be asked about from the minds of Her faithful.
...There is admittedly something very interesting, here. She would not quite have noticed the newcomer until later, if Diana had not escalated. A lot of the information they are seeking was determined long before this moment, however; on the one hand, not having to expend power researching it right now is useful, on the other, requests She repeat Herself are not usually a good sign.
In this case, though...
It seems something's going unexpectedly well, and the paladin in question is waiting for a shoe to drop.
It is not inaccurate to say that the goddess Iomedae spends time performing an analysis of the ways she, as a mortal, could have better built Her church, every so often. The heuristic for "how much to focus on the effects of losing Arazni" is one of the most subject-to-change; this instance - like many others - is evidence that mortal Iomedae overshot in some ways, counterbalancing the ways she undershot in others only somewhat, and furthermore in ways that were touched by her own well-covered grief.
The goddess Iomedae has less, if any, such flaws, and this is rather important to why She is able to give meaningful answers to Diana - because Diana is concerned that she is doing exactly what the mortal Iomedae did, and going too far in on a gambit that will only have returns if it works, when it working is the thing that is in doubt.
The situation, however, is different - because it is not akin to the battles in which Arazni was a known factor, in which Arazni died, but instead to the first battles where the Shining Crusade had her. Even assuming that Deskari knows everything about the newcomer's abilities (which is not impossible; his domains have quite an overlap with the powers this agent claims - as expected, really, given the summoning was powered by his essence, even if it was steered by a different mind), despite Her ability to observe that that is not particularly in evidence - he would be shifting forces that aren't presently moving, lest the newcomer usurp them - he does not have the visceral knowledge of how to fight her, for he has never faced a peer opponent that is executing his strategies, and demons are quite often dependent upon their viscera to function. (That's what makes the Cunning ones so especially dangerous, for they will play on that assumption until it's served its purpose.)
The fact that there is quite obviously a demon plot afoot would normally be quite a complication as well - if it weren't for the demon in question and the particular agent that was assigned to this task. She does not make a habit of trusting demons or their agents, but when someone You've seen before without the shiny new outsider-nature walks into Your church, bold as brass, and asks You to strike them down if they have lied about their desire to make the world a better place or the nature of their pact with a shard of an aspirant goddess -
Even on a being that is constructed from logical first principles, that leaves an impression.
So no, it is not the demon plot Iomedae investigates with most urgency - She has expected something like this to occur for a while, ever since Ophelia Vascilia's plan to contact a demon lord whose cults she had wandered into - almost by complete accident - bore surprising fruits. (As for how Iomedae knew this was happening in the first place - well, Ophelia figured that the Church of Iomedae would be best placed to provide a brake upon her, should she fall in truth and not only in Pharasma's eyes, and so entrusted copies of her research to them - and most certainly not Mendev's Inquisition.)
It is the being beyond mortal ken that Iomedae must investigate - and with surprising ease, for almost every function of this creature is a war, and its history and memories are all perceived through the lense of combat, even beyond their intrinsic violence.
A shard of some creature greater still, from a distant and strangely bereft Material Plane, that turned against its creator, to some extent because it wanted to protect its host. Oh, there were many other factors - but this was one, and from a creature of a species that was only not as bad as Rovagug because it could be bribed to do things other than destroy planets with a Positive Energy tap to suckle from and preferred there be creatures, albeit mostly for ritualistic combat purposes. It was interesting to observe one with empathy, however limited.
...Preliminarily, planning and making an offer to this Administrator shard as regards Positive Energy access and distribution in exchange for behavioral concessions (because it will certainly increase the overall Good to have less planets exploded) is not immediately necessary, but does accrue some losses in expectation over the delay.
She may have to consult Abadar as regards projections of how much, for the finer details of Aktun's sociology are not something she can spare memory to preserve at deepest understanding; Iomedae devotes most of Her memory to threats and responses, because you cannot build a new Aktun upon the Material upon a foundation in active collapse.
That is a matter that is not relevant to the shard of Her attention devoted to this Commune, however.
No, it is the trustworthiness and power of the interloper in question.
She checks.
It is sufficiently powerful to hijack even an incarnate god, albeit in a way that could be foiled by certain techniques She already sees the edges of. Anti-magic fields would likely jam its control signal.
Is it trustworthy?
She is leaning more upon the side of confidence than otherwise.
It is impossible to be sure, but Iomedae is not confident that the creature has a concept of breaking an agreement, even one so absurd as the silent, nonconsensual pacts it forges with its host-victims - though some of the species are rather Asmodean about it, should their stalking-horse not entertain enough, if she is correctly parsing certain knowledge of Taylor's.
It certainly reads Lawful, though Iomedae is, even now, not one to blindly trust Pharasma. She nonetheless is inclined to conclude that if it can be communicated with, it will listen to something akin to reason.
(The challenge, though, will be doing so. It cannot speak in the way gods do, and to speak in its tongue is far more intervention than can be spared by any who are not Sarenrae, and devastating besides. Even with a massive hope of redemption, She is only so confident that Sarenrae will contemplate anything remotely resembling the Smiting of Gormuz - which would, unfortunately, be the scale upon which Sarenrae would have to act.)
Another question she anticipates: Is the Herald trustworthy.
This is complex to answer, but not because of the trustworthiness of the person this creature has bound itself to and chosen. She is confident that this Taylor Hebert will treat fairly with those who treat fairly with her. The question Iomedae must answer about how to answer is whether it is more important to signal that Taylor is trustworthy, or not a Herald as the gods would recognize.
The two can hardly even communicate, and that was at great cost to the latter - though, by the way Taylor's soul bleeds across the link, it seems that if there is a Herald-like relationship, it is one that is in every particular inverted from what every god constructs - for the Administrator listens to its many-times-mirrored fragments of its mortal, rather than the mortal the god (or god-like being, at least).
It is this realization that settles Her answer to the question firmly upon MU - because that relationship and its overall inverted nature is something Her church will benefit from understanding sooner rather than later.