Black Powder & Dark Magic
Dragonborn are descended from dragons and humanoids and as such they bear those characteristics. Hailing from the distant land of Arkhosia where the Tumerian Dynasty has been in power for over a thousand years. A nation that has been that powerful for that long would logically hold interests in expanding to different continents but the Tumerian Dynasty is constantly under attack from the smaller, less powerful clans so has little time to consider expansion.
None the less, some dragonborn have traveled to and settled in Vaporia. These immigrants are strong and possess clan ties every bit as intrinsic to their existence as their native cousins.