The Legend of Korra - Book 2: Spirits

 Spoiler

Somehow I doubt it's going to be Varrick, because I feel as if they need to make the next season even more grandious. Seriously,

Season 1: OH NO ALL BENDERS ARE UNDER ATTACK.

Season 2: OH NO THE WHOLE WORLD IS GOING TO EXPLODE INTO DARKNESS AHHHHH.

Yeah...I have no idea how they're going to overcome that, but downgrading to rich Varrick being the villain is quite anticlimactic. It's going to have to do with Spirits, obviously, since the merging of the worlds and all.

Also, hoping Azula and Zuko shows up. I didn't realize Part 3 of The Search was released last month and I just finished it.

 Spoiler

They don't need to. The entire world has just become open to Spirits again. They roam free. There's all kinds of intriguing possibilities that don't necessarily have to be pure evil like Books 1+2 were. That's why I like this ending even though I wasn't really too fond of the finale itself. The lore can expand so much, it can become so amazing.

I don't think Varrac will be a main bad guy either. He's being used mostly as comic relief, and he's the only comic relief that's actually working so far, at least in my opinion. His position wasn't exactly evil in this season really either. He was a Southern Water Tribe member who wanted to get Republic City on his side, and knew the only way to do it was to gain power. The kidnapping plot is going a tad far, however overall his motives weren't exactly pure evil. He's clearly one who has his own plans, but being the big bad is not one of them.