In Man from Mundania, Grey seems to exhibit the whole "unbelief" thing. Grey = TC
Good Magician Humphry = Mhoram
A long shot, I know, but it makes sense to me.
Com-Pewter = Lord Foul, of course!

The demonesses Metria and Mentia = Daphin, I think.
Smash Ogre = Bannor *dodges pebbles*
Iris = Atiaran
Irene = Linden
And my personal fav, Grundy Golem = Amok
For those of you who like Xanth, help me with the comparisons!