Haven't updated in ages; so here you go! (I wrote this in all of half an hour, so...yeah.)
Although his comrade-in-arms - and the closest one in their little 'gaang' to his own age - Sokka really didn't think of Zuko as the Fire Lord.
Oh, no - he'd never called Zuko Fire Lord. Nobody had, even back when he was chasing them around on those ridiculous rhino-horses.
Mostly because Zuko is still socially awkward, passionate and bone-headed, even though he's ruling a nation.
So when said bone headed male goes and bends lightening like it's nothing, or helps redirect the flow of lava away from a city in the far reaches of his nation, Sokka once again marvels that he had once thought that the man and his father embodied evil.
Naturally, he'd been shocked when he found out Zuko had moon-lighted as the Blue Spirit, though he wasn't sure why anymore - everyone but him had had a crazy hero gig going when they were younger, it seemed.
What had amused Sokka - and confounded him - was that the mask Zuko had picked was blue and white, the colors of the Cheiftan's own nation.
It was a little odd, having to correlate the heroic, dangerous and mysteriously vanishing Blue Spirit with the - at the time - nefarious, deluded and brash banished Prince.
And yet...Zuko, no matter his face at the time, is still every bit the man who he had helped overthrow a nation for, no matter his impatience.
And resting a little easier, Sokka sighed, closed his eyes, and let the sounds of the tiger-seals wash over him.
