If you mean how he got there, he was traveling on his bison and got caught in a storm and had to protect himself via freezing.

Yea that

When the first episode bought up about the spirits and trees and shit... I thought it was
Gonna be about how ppl deal with spirits living wit them.. And yet the show has not continue that route.. Like did they even fix the tree/vine problem that kept growing lol

I imagine they will address that eventually.

I want to see the next big battle. Korra lost connection to all previous Avatars didn't she? So she can't go into 'Avatar mode' and become a lot stronger

I'm hoping there's not gonna be an event where Korra has to go to the spirit realm to find her previous carnates to restore her connection

yes she can, since she is connected with Raava
she just lost access to the knowledge of previous avatars

fortify city with giant metal walls
fail to protect against tunneling earth benders

Wat? Lol there was a traitor who helped then escape and get in

This.

Anyone else notice that the fire mind bender can guide her attacks? I thought that was pretty cool. And lava bending is op

So he was the only one able to detect a subterranean infiltration? Hmmmm