I think there is a difference between the Head on a Pole and the visions. Geoffrobro had a very interesting idea on the Head that was unfortunately lost in The Cast That Is No Longer a Cast so I'll try to summarize his point as best I can remember in the thread for it.
As for the Visions, I think there is some parallel between Suabon having seen himself, cast back, as he was dying and Kellhus' visions. I venture to speculate that perhaps that is a major clue to build upon, proof that the Principle of Before and After is well and false when it comes to the Outside leaking into the Inside.
This is what I believe happened on the Circumfix: through the near death experience and cipher* of Serwe, Kellhus is open to the Outside. In that moment, Kellhus himself comes to him and at that moment, the vision of the future is that of Kellhus becoming or being under the influence of the No-God, that is, that Consult wins. Why? Well, we might get an answer in the form of what Kellhus tells Moe when he kills him. He says that Moe would choose to join the Consult. So, as such, perhaps the vision speaking with the No-God's voice is the warning. Kellhus will
be the No-God if Moe is allowed to live. Notice, the vision, as far as we see, never actually tells Kellhus to kill Moe. However, he says in TGO that the voice in the vision did tell him as much. So, it wasn't a straightforward command, but rather a dire warning about the path he was on. I put a good bit of weight in that scene where Kellhus ponders the twig at Kyudea, which is a cast back to the twig of the prologue. It is here, the warning from the vision that he sees the branching of the path and chooses the one that leads to the death of Moe.
Now, cast it forward, Moe is dead, Kellhus has averted that future, so the vision is different now. The war is somewhat beyond that of simply Kellhus versus the Consult. Now, the stakes are higher, or at least
different, it isn't just about averting the No-God, it's about warring against the Hundred. It's about ending damnation all together, without the No-God. It's about Kellhus being the Zero-God, the Absolute.
In TGO, Kellhus tells us that the Voice is not sane. He tells us he doesn't trust it. But he still listens. Why? Because what it tells him is correct. What it tells him from the future
happens. Kellhus directs himself from the future. Before and After is sane. The voice is beyond that. We've asked ourselves time and again, why this, or that? What allow Akka to live? Why allow Fanayal to live? Why the Great Ordeal? Why everything with Proyas?
The answer to all of these doesn't lie in the past, it lies in the future. It's not about what happened to lead Kellhus to choose this path. It's about what all of them will do in the
future. Akka had to be free, because Mimara would run to him. He would impregnate her. She would have the Judging Eye then. Fanayal lives and so Mommen is destroyed. Why disillusion Proyas? Because he needs to be a doubter, probably to accept Akka when he bring Mimara. All of these things are key for some reason. We can't see exactly why just yet, but we are drawing toward them. The future is the key.
This also explains that lack of "definitive Kellhus" in a way. Why were all the Dunyain kids unable to fathom Kellhus' personality? Why did Theli conclude that, "There is no such man as Anasûrimbor Kellhus … No such Prophet. Only an intricate web of deceptions and stratagems … bound by one inexorable—and as you know, quite ruthless—principle." This is because Kellhus is as directed as those he directs. He is both a cog in the wheel of The Thousand-fold Thought and it's engine. Why is he working so hard on Salvation? Because he knows that if he fails, he too is Damned.
*Bakker said (and I can't find the quote at this moment) that Serwe is an important cipher in the series. I was curios, so I looked up the definition of the word and was a bit surprised to find:
#2 of which is of particular importance, considering what we now know of The Absolute in relation to Zero and the Zero god.
