The Termana hardcover has information on the charduni; however, I didn't find it to be so great, personally. The book is worthwhile, however.
Then there's the Faithful and the Forsaken...the charduni stuff in there is good. More or less. However, one of the strongest points running throughout their part of the book is just this side of directly contradictory to Scarred Lands canon. That is, no one is allowed to prevent people from worshipping the gods without getting royally screwed (as has been evidenced in every other book except the Faithful and the Forsaken; even Mithril has shrines to Chardun, Belsameth and Vangal). The fact that it runs against the grain of this setting element without an explanation degrades the fact that the charduni part of the book is fairly well written, unfortunately. Good writing with a bad idea.
Then the mechanical aspects of the charduni in the Faithful and the Forsaken are fairly atrocious; from the Once-Charduni feat to the two prestige classes, they're really just poorly thought out.
However, disregarding the problems with the charduni part of the book, and you get a good glimpse into their psychology and culture. They're the saving grace of an otherwise bad book. Even still, it's not worth the cover price; if you could find it for, say...$8-10, I'd say it's worth it. For what I got out of the book, I'd say that covers my general reading enjoyment and what I might even think to use out of it (much less actually use, which is currently nil; however, I judge the worth of a book on what I might used, as opposed to actually do). The charduni don't even take up half the book; I believe they've a good ten pages or so less than the elves.
I wouldn't necessarily recommend the Termana hardcover for the charduni, but I would recommend the Termana hardcover, and it does happen to have a decent amount of charduni stuff in it, and though I would recommend the Faithful and the Forsaken for the charduni, I wouldn't recommend the Faithful and the Forsaken. That make sense? Heh...anyway, those are the two major sources for charduni information, but I find both, unfortunately, have their weaknesses.
But you get my drift. In any case Thornir, yes F&F will probably be of use to you. But get SLCS: Termana just for clarity's sake.
