Interesting. But I find the idea honestly unlikely. There's too much dependency for LLMs (I dislike the term AI for these things) for them to spread or connect together in drips and drabs successfully. I don' think the "rogue AI demon in the walls" is probable without deliberate human action to create it. (Not that humans wouldn't be foolish enough to do such a thing— just that it's unlikely to be accidental or "evolutionary" in nature.)
Great story idea, though.
I note that all three LLMs try to skirt around the issue, addressing every comment made— even the joke about IT people having no fashion sense.
No, really, Grok. You can ignore that bit. That's just for people.
On a side note, it's interesting that "demons" as we picture them today are not at all what the Greeks meant by the term. A daemon (Anglicized into demon) was not a hellish creature of the nether world, but merely a spirit of inspiration or drive (for the most part), somewhat divine, often seen as beneficial, but equally likely to be detrimental. Sometimes it's meant as a personal force tied to an individual, both the result of and the driving force behind that person's actions (as, say, Alexander the Great's determination to militarily conquer every culture he encountered combined with his apparent ability to actually do so).
To the Greeks a daemon was neither good nor bad, and contractual agreements or deception of the human, or the desire for his soul, were not part of the mix.
The Judeo-Christian interpretation of demons as rebellious, deceptive, and evil spirits capable of possessing a human, possibly even against that human's wishes (or possibly with it), is a later development. It is clear that at least among the Jewish culture, and possibly even Greek culture, demons had become associated with inexplicable, harmful human behavior or some sort of tainted precognitive or "extra-natural" awareness, as speaking truths which others did not see. It is also clear that the idea of demonic possession in this light was always negative. Sulfur and horns, however, had nothing to do with it, nor is there any idea of contracts or even the claiming of souls. (Jesus' famous transfer of Legion into the pigs is the closest we see to any "legalistic" element among the demons— they would bargain, they would make agreements, and would carry out these even to their own destruction. It's an interesting note that the drowning of the pigs does not seem to have been either the expectation of the demons, or of much concern to Jesus as to the final outcome— he considers the matter finished, and the demons are presumed to be as dead as the pigs. But I digress…)
In any case, the "AI" Demons would not be capable of actual human possession, just persuasion of the desperate, greedy, and gullible. The spirit of decision will still be the human's.