One for one, don’t think that the Spirits are antagonists in this book. In fact, if we look back, the name of a book doesn’t connotate the villain’s alingement (such as with the fact that Amon was the villain of Air yet was not an Airbender). I think there’s a reason for them attacking…
In fact, I think the Dark Spirit is going to turn out to be the Anti-Hero of this book. The Dark Spirit, even if it was voiced by the same person who played a major antagonist from the first series, probably isn’t going be the case with this season. At least in my opinion. Then again, there are voice actors who have played almost the same kind of character in either series, (like with Hiroshi Sato and Fong, or Long Feng and Yakone), I’m going to place my thoughts on that the Dark Spirit is going to be revealed as an Anti-hero who is trying to save his/her fellow spirits from total annihlation at the hands of what she/he considers “evil humans”.
I think the spirits are being brought out because there’s been a major upset in the spiritworld. They’re basically like what Hei Bei was in the original series, upset and lost. They seem aggressive because they’ve been thrust into an unfamiliar space.
I don’t know about any of you guys, but I think Unalaq is going to turn out to be a villain. I know Bryke seems to have this thing with brothers/siblings; THEY NEVER EVER GET ALONG, OR THEY’RE AT EACH OTHER’S NECKS. One of them always turns up evil, or something on that level, you know unless they happen to hook up with the Avatar or something… I think Unalaq and Tornaq are going to have this Mufasa/Scar kind of confrontation, and it won’t be pretty.
I have a feeling that their relationship as brothers is going to factor a lot in this season. In fact it’s going to relate a lot to Korra’s role in her destiney and the destiney of the Water Tribes.