The Legend of Korra - Book 2: Spirits

 Spoiler

probably being reincarnated into some other schmuck.
Though, when Rava was destroyed she appeared inside the Dark Avatar, so I'd imagine that Korra has part of Vaatu in her now, unless, like I said, the Dark Avatar has a cycle now.

 Spoiler

But that only happened cause vaatu went like in korra's mouth and pulled raava out and pomegranate, right? lol