So Nickelodean released this at Comic Con...

Yeah, I'm excited as hell, but this trailer shows a lot more than you may initially realize.

Here's what we knew before this trailer:

The story takes place some 70 years after the events of the original series.  Aang has died, and Korra is has been born in his place.  She is from the Water Tribe, and at the start of this story, she's already mastered Water-, Earth-,…