Elania al'Manir
Aes Sedai
One of the things we've been told would never be explicitly revealed was how Rand and Moridin swap bodies at the end of the series. Thanks to an on-point guess by a Redditor, followed by confirmation from Brandon Sanderson, we now know the mechanic of it.
u/Dirkinator
So, Rand did die but he was reborn into Moridin's body? Again, I was confused by the ending because he had the saa and so how did Cadsuane recognize him/how would any of them recognize him? Where is he going?
I made a post a while ago about this. Casting balefire requires the soul of a channeler to wield it, like a man holding a sword. (With possibly the exception of terangreal that create balefire) When their beams crossed, it became one balefire with two wielders. This paradox essentially linked them.
Balefire removes objects from the pattern, but... it cannot remove other balefire. Balefire isnt an object. Balefire is cast and directed by one person, usually, so it's linked to their intentions, their soul perhaps. The balefire that crossed paths became one beam, as it cannot remove itself from the pattern. One beam, linking two souls as it's wielder. That is why they were linked. As for the body swap...
It's pretty clearly shown that what happens to moridin, Rand feels, and vice versa. I think this is because balefire, by its nature, must have a soul directing it, and it cant differentiate between one person or the other, so they become merged. Both were in control of the beam, so for a split moment, they were one.
This lead to the very strange phenomena of Rand experiencing Moridins physical experiences. So think about that: what Rands individual body experiences, Moridins soul, awareness, whatever you want to call it, Moridins soul experiences. Including death. Moridin died, as Rands body died, and Rand lived, as Moridins body lived.
Basically, the body swap had already started to happen the moment the beams crossed, and when rand "died" it was completed
TLDR: they had already swapped bodies. The moment the balefire beams crossed. Rand bodily death killed Moridins soul, and Moridins body surviving allowed Rand soul to live. "To live you must die"
Long shot, but u/mistborn, any chance I'm close? Apparently you're allowed to confirm a correct theory?
u/mistborn
Disclaimer: RJ wrote this sequence, not me, and he didn't always leave great explanations of why he wrote what he wrote. (He was focused on getting me the information to write scenes he hadn't had time to write.) However, to the best of my recollection, what you outlined here is basically what RJ intended--though with a little tweak to the second part. I believe in the notes (or it could have just been Harriet relating it to me) he said, "The soul that wanted to live found the body that wanted to live, and the soul that wanted to die didn't go to the effort." (Or something to that effect.)