Intelligence without a soul is what they cant see.
As I got it, in bakkerverse intelligence and soul (also, intelligence and ability to mess with onta) are tied together like factory and it's product, like cause and result. Though I'm having a big difficult of quantifying/qualifying things here.
Him being invisible in the same way the consult machinations are seems like a fairly likely situation, but I can't seem to make sense of it
I've remembered an old theory of mine, maybe we can use it here.
1) Gods are so beyond of mortals' entanglement with time. Every one of them is a sum of all possible timelines, divided by exact principle like fertility, conflict, fate etc. It's easy to visualize such thing as 3D-puzzle (∞D, actually) or as regulatory and coding regions of a DNA gene.
2) Having a way to be in every possible situation, gods actually have constant and different experiences of their own undoings due to uncountable reasons.
3) On the one hand, they are "accustomed" to such experience. To them it's just an everlasting border of their existence, just like field of view or memory threshold for human.
4) On the other hand, such experience is so overwhelming it "leaks back" onto it's critical reasons -- places, people, concepts, etc -- and makes exact details highly unrecognizable, if not insignificant.
5) Thus an intelligence without a soul & a little boy Kelmomas may share just one quality. Their phenomenon somehow directly leads to gods' undoing, probably through different and unrelated means. But it's not a big deal for gods, for they just lose interest in such timeline, focusing on possibilities where Arc never landed, Kelmomas was drowned for deformity, Kellhus is narindared.