What is Project Korra Spirits?


I've looked around on the forums but I couldn't find a post that mentioned much about what this plugin is, or atleast, what it's going to be.
I looked on the wiki too but there was just a short paragraph about it.

I know there isn't going to be much said, since the plugin isn't made and from my understanding was left for a while to focus on 1.6.0 of the Core.
But could anyone just give me a rundown of what this plugin is going to be?
I'm guessing it will include spirits to interact with, but maybe I'm wrong.
Will it also include the spirit world?

The main reason I'm interested is because if I know more about what the plugin is going to be, I can start to suggest things on what to add and such, as I'm already looking forward to the possibility of spirits in minecraft.