(Beware Deux Ex Machina. Kirsey can't be the solution to your story. It has to be Merran and Melayne. Everyone else is just an accessory to the plot.)
I mean to build up Kirsey and the sorcerers he's trained. Then I mean to show the limits to that kind of power. (You've already seen previews. Uemiska's skill at debate is another kind of power.)
FYI, I have a few titles for books late in the story. If I can get that far, the last three are Dies Irae, Dies Illa, and Riot and Rest. (The last comes from "It may be we are meant to mark with our riot and our rest ...".)
There's a mystery I've hinted at and some of you have half-caught it. The book where that comes will probably be titled The Gate of Broken Seals. ("In the Gate of Treason, in the gate of broken seals,/'Bend and bind them, bend and bind them, bend and bind them into wheels./Then once more in all my garden there may swing and sound and sweep/The noise of all the sleepless things that sing the soul to sleep.' " Wonderful and terrible to declaim, and you can find the source easily enough.)
There's another theme to add, if you like: For the end of the world was long ago, And all we dwell to-day/As children of some second birth, Like a strange people left on earth/After a judgment day..