Epilogue
When Sokka is closest to Zuko, no one is more surprised than either of them… and no one else quite understands it like them either.
On the surface of it, they have so little in common that their initial clashes are almost clichés: angry jerk versus careless dufus. Fire versus water. Prince versus peasant. Their lives are as different as their family histories. And yet- and yet, family is really how they bond.
Not simply in a daring jailbreak of Sokka's father from prison. Not simply a post-war tracking of Zuko's mother. Not simply in shared sympathy for the mutual miseries (of entirely different sorts) resulting from their sisters.
It's what else family is. It's the trust that forms for seemingly no other reason, the easy animosity that vanishes in the presence of true danger, it's the ability to rely on, to trust, on another for no other reason because you can, because for all their (many) flaws that person is still trying to be a good person, and at the end of the day you find that you have to many things in common (a desire your peoples, a vague nebulous plan for the future, or simply an eye for the ladies) to throw it all away for anything.
There are a lot of ways it could have started. Treason, mutual imprisonment, mutual reliance, a hundred tales could have been told. But it always seems, at the end, to come down to the equality of brotherhood.
After the War, Sokka surprised everyone by eventually going with Zuko to the Fire Nation, formally as the Water Tribe ambassador to help in the post-war rebuilding and diplomacy effort, informally as one of Fire Lord Zuko's most trusted advisers, and actually as a determined pest who never stopped dragging the normally serious Fire Lord down to the streets of the capital to lighten up with the commoners. While Sokka's antics often dominated the court gossip, few could deny the Fire Lord's easy humor when the man was around, or could avoid the fear of His displeasure when any political maneuvering against the Tribesman was discovered.