during the spell plague (you'll note an aweful lot of stupid bits of FR lore start with "during the spell plague") Asmodus became a god by consuming Azuth;s divine spark. his followers then did a ritual that claimed all teiflings in Faerun, no matter the herritage as "his infernal bloodline" absolutely stupid, the best I can figure is WOTC did this so they could eistablish a baseline of what teiflings looked like, but yeah... ABSOLUTELY stupid. FR is still recovering from the absolute rape that 4th edition did to the lore
Meh, most of it was retconned anyways... as far as subraces go: I think they have to cut it off somewhere. I'd honestly rather have stuff like Genasi and Aasimar, then say winged Thieflings. Also, if you introduce winged subraces, you gotta do flying, which would be rather broken in a game with that much verticality... then again, that could mean Fey'ri and Avarien could be a thing too.
Nah, better not...
