Fridge Brilliance: It seems weird for Sokka to be spiritually gifted, since he's very much the Agent Scully for the Avatarverse. But in some stories, mundane people can gain something after interacting with The Fair Folk or demons. Sokka became the unknowing vessel for a wendigo seed when he was young, which granted him enough spiritual prowess to speak with the mountain spirit while the Yu Yan archers probably never were exposed so long to such creatures, so they couldn't hear the mountain spirit talking.
Tear Jerker: Zuko's entire world comes crashing around his ears when he's implied - and later confirmed - to be the Avatar.
Unexpected Character: Aang is alive and he's implied to have done something to be excluded from the Avatar cycle in exchange of becoming a guide for the new Avatar. Of course, this isn't much of a spoiler if you've seen the character tags.
