Grey DeLisle (the voice of Azula in A:TLA) has said she’s coming back to voice a Spirt character. We also get to see a frightening Spirit Wolf in The Search: Part One (and he’s on the cover of Part Two, so his existing is not a spoiler). I think it’s fairly safe to say that we’re looking a slightly more super-natural villain than we go in “Air." 

As for specialized Airbending Technique, I’m not sure. We know the Air Monks were super peaceful and respectful of all life, so I dont think it’s going to be as violent as Bloodbending. Until Korra learned to Spirit-Bend at the end of Book One, I would have thought that was the Airbender technique. 

There are so many places that you can manipulate air, maybe this specialized technique is something discovered by Korra, since the Airbenders have been wiped out during most of both series’ runs.

Any guesses out there?

-Da7e-