It seems to me that there are two entities on Athera which incorporate a myriad of maddened, insane entities bent on possession and destruction.
The first is clearly the Mistwraith - trapped but not quiescent in Rockfell and the rest on Marak.
The second is the Koriani Great Waystone which contains the maddened shades of failed Prime successors, and possibly the previous Primes. Oh, and one maddened iyat to go with the enslaved consciousness of the Waystone itself..
Trys I was just wondering if that last line qualifies as a spoiler?
Thanks for catching that Roisin, the whole thread's been moved here.