[@Dark Cloud] Ravnica is as much one of the planes that exist within the wider WotC lore as much as Ravenloft is. Both are entirely separate planes to the FR, and any races from Ravnica have as much business being in the FR as a race from Ravenloft does.

That said, I'm fine with going with the aarakocka I mentioned. I thought you were restricting races for balance concerns, but if you're not corned with that I'll play a bird person. The Ravenloft legacies are on par with flight built into the race when it comes to power level, so my concerns about playing an overpowered race like the aaracocka are put at ease.