I don't think they've told that, either! But it makes sense since Korra will enter the Spirit World. And I think Mako's a jerk, too.I hated him in that episode when he went all bitchy with Korra and said that their friendship is over and then when it turned out she was right he just asked her if he could come live on the island with her! But they needed to create some tension between them and I also think he turned out looking as a jerk because the whole Makorra relationship was so rushed. (And truth be told, I think he looks better with Asami) Fortunately, now they have all the time in the world to actually make him lovable.Besides, I don't think he's that bad, he actually reminds me of Katara because he's so motherly.