Here is an enigmatic tidbit from the Pavis Common Knowledge book (page 11). Apparently this happens post-Troll invasion:
"Iffinbix was the name of a settlement which lasted until about 1400. It centered about a god of that name, connected to the earth, but with some sort of sorcery as well. Yojarl Thirdeye was the name of their leading hero, who showed how to eat the Agipith root which lets worshipers across the threshold of their temples without harm. When their temples are found even now, the root must be eaten to ensure safety. These temples are easily recognized by their four-sided sloped, slate roofs."
So Iffinbix is an earth deity who teaches sorcery and requires people to eat a spiny Praxian cactus to enter his temples. I could see how this might be of value to rubble survivors, but trolls could eat such a cactus pretty easily I think.
So does anyone have any clue as to where the settlement of Iffinbix might have been, or any related information? Feel free to speculate wildly, as this one is a head scratcher.