I am running two different groups through Reign of Winter at the moment. One of the groups just arrived to Triaxus.
I have been coming up with different spells to allow the sorcerer's here to use. Wondering what other GM's did here to help bring in the realization that the PC's are not in Golarian any more.
I was going to add a few spells that made sense and were "good" relative to Triaxus' "super-seasons". Like a 4th level Hibernate/Cocoon spell that lets you age only 1 day for every year that passes, and automatically wakes you up when the season's shift. Good for Golarion casters? Not really, it means you age half a day and 6 months go by. But on Triaxus...
Also, how certain spells would interact with the culture. Since the dragonkin are any alignment, but true dragons are rather fixed in their own alignments, I can see all but the more restrictive cultures having a rather high disdain for Alignment Detection spells, oscillating between "it should be obvious" and "invasion of privacy".
In the Drakelands, certain types of spells might be frowned upon or even illegal. In a white dragon controlled zone, even alchemist fire might be contraband.
Also consider that the relationships between riders and dragonkin are very interesting. While the two races are probably more integrated and equal within their society more than any any two Golarion races, there are still massive divides like size and if the relationship gets intimate. So massive that some cities have basically gotten on the map for going against the norm.
To me it seems a MAJOR theme of Triaxus is a concept of stagnation/endurance with occasional spikes of complete 180 degree shifts. The seasons shape the inhabitants, literally and figuratively.