True, true: they've really formed a tight sisterly bond and it's really cool to see them work together the way they did in Book III, but also seeing Asami comfort Korra at her low points like right now.
I've re-watched it a lot recently as well, and ATLA really is fantastic and deserves the praise it gets, but it's a shame people don't see that LoK is definitely a worthy successor to it at this point. Really? Wow, I was actually very happy with Zuko in Book 2 compared to Book 1 where he came off as incredibly single-minded and shallow until the Siege of the North, where we began to see his real colors. Most definitely, man.
That's really deep: actually interesting.
Glanced over your fic, but going to need time to read into it a bit more before giving some constructive criticism: it seems pretty good to me so far.