OK, so I think I've figured out part of what's going to happen in the final series of confrontations at the end of Tarmon Gaidon.

Part of it was triggered by Ryan's post below about the importance of Lanfear (being the one who drilled the Bore in the first place), and part of it I have put together over time, based on numerous quotes and gut feel.

First I need to demonstrate that we have seen a number of quotes over the course of the series that have foreshadowed the eventual fate of several of the Forsaken long before they eventually met their fates.

In Book 6, Semirhage mentioned that one way of winning the game of sharah, was to let your opponent capture one of your Spires (an important piece equivalent to a Forsaken) and then using it to lead him into a trap. She then muses that she would not let herself be sacrificed in this way. This was highly ironic, considering that this is exactly how she ended up. She was captured and used to trap Rand, and eventually sacrificed so that the Dark One could tempt Rand into using the True Power and turn him into Dark Rand. Perfect foreshadowing, as it turns out.

In Book 11, Arangar muses that she intended to use Graendal, and not get caught in one of her traps. Well, in ToM we see that this is exactly what happened to Arangar. She is caught in one of Graendal's traps and sacrificed in order to give Graendal a brief advantage. Perfect foreshadowing again.

Now I want to ask a question:

Assume the plot requires that you save one of the Forsaken for a role right at the end of Tarmon Gaidon, and assume further that the role you have in mind also requires that this Forsaken be the one who has the most hatred for the Dragon, and is the one who is most eager to confront him directly. This dual problem is a dilemna indeed, given that every Forsaken that has engaged in any type of direct confrontation with Rand, has died or been utterly defeated.

How would you save such a Forsaken for the very endgame, where you need him to further a crucial part of the plot, while at the same time retaining this sense of personal hatred for Rand al Thor? Why, you give him a secret mission that forbids him from taking an active role during the rest of the series, and in fact makes him completely invisible right until the end.

Just to link this to some references, which can be seen to show exponentially greater foreshadowing than any of snippets that have predicted the fates of previous Forsaken, here are a few quotes:

Book 6: Mesaana assumed Demandred had more than hearsay about the "useless rubbish" in Tear, else he would have had his sa'angreal and launched himself at Lews Therin long ago.

Book 6: Mesaana: The past was idle speculation. All that mattered was that Demandred hated the Dragon, and had transferred this hatred whole to al Thor.

Book 6: Graendal: Sammael knew his hatred for Lews Therin paled next to that of Demandred.

Book 9: Demandred: "So it seems he must be killed after all. It was difficult to hide the satisfaction in his voice."

Book 11: Arangar: He was a fool to think that. To think that he might have been the Dragon had things turned out differently.

Book 12: Demandred: "Semirhage knows that had she killed him, I would have claimed her life in retribution. Al Thor is mine. Nobody kills him but me" (pretty clear, or what do you say).

The point is, all of the above foreshadows very heavily that Demandred has been created for the sole purpose of taking severe action against Rand. And the fact that he has been hidden for so long indicates very strongly that this assault against Rand must be saved until it has significant impact on the series as a whole. Anything else would be a massive anticlimax.

So here's my theory:

Rand is going to confront Moridin at Shayol Ghul at the end of Tarmon Gaidon. And Moridin will be winning. Then, at the last moment, the link that exists between Rand and Moridin will allow Rand to somehow exchange bodies with Moridin (a theory that has been raised many times before, and I won't go into the detail supporting it at this time).

We will then have a situation where Moridin (in Rand's body), will be standing over the almost defeated Rand, ready to kill him.

Demandred will then arrive on the scene, and seeing his arch nemesis, will finally take the action he has so long craved for, and kill the Dragon. Only, it will not be the Dragon, it will be Moridin in Rand's old body.

Someone - maybe Rand, maybe Alivia, will no doubt kill Demandred then. But the point is, he would have fulfilled his purpose in the series.

Rand (in Moridin's body) will now have control over the 2 mindtraps of Cyndane and Moghedien (incidentally also the two most powerful Chosen in the Dreamworld). Perhaps Cyndane's knowledge will then help him to seal the Bore in the same way it was originally created - probably in TAR, and probably in a similar way to which Perrin has learned to shape the Dreamworld according to his will. Maybe by simply willing it shut, it will seal itself, if your will is strong enough. Maybe if you are linked to two powerful Dream World Masters, like Lanfear and Moghedien it increases this chance.

In any case, that's the series of events that I foresee happening.

Moridin almost defeats Rand.
Rand swaps bodies with Moridin at the last moment.
Demandred kills Moridin, thinking he is killing Rand.
Rand now has control of Cyndane and Moghedien, and does something in TAR to seal the Bore again, with the help of the woman who drilled it in the first place.

I'm pretty sure Demandred will be killed after learning of his error, but whose hands that will be at, I cannot say.

So, there, that's my theory. What do you think?