Aang and Zuko—sunshine boy
When Zuko sees Aang, he no longer sees the avatar, the person he needs to restore some abstract concept of honor, the legendary bender who will save the world from his family.
Instead he sees a child of only thirteen, round-faced and bright eyed. A child who despite carrying the weight of the world and the tragedy of losing his entire nation, is goofy, energetic, and unfailingly kind. Someone who he had hurt in a misguided quest yet still forgave him completely, wanted to be his friend. Aang was a flicker of hope, the brightest person he knew, except for maybe his uncle. Zuko always felt like he was suppressing a smile when he saw him.
He watches him train, running through the beginners katas with the grace of an air bender, even if the forms weren’t executed quite right. He stumbles, landing on an air ball he creates to stop the fall, and somehow a carefree laugh escapes his chest at his mistake.
Despite the weeks slipping by before Sozin’s comet, he’s still the light, happy, wonderful Aang he was before.
And it scares him terribly, to think of such an overeager ball of sunshine facing his father.
He was the same age as Zuko when he dropped to his knees in supplication, begging grievously for the mercy of his own father, and received his fire instead.
Unconsciously, his fingers come to stroke the rippled and damaged flesh of the scar his father gave him as he thinks, ignoring the whispers of pain that follow.
The pathetic excuse for an Agni Kai had burned away his innocence and replaced it with cold determination to restore what he had lost. He dreads the same thing happening to Aang if he were to go up against his father with anything less than a perfect fire bending technique.
This was the man whom he would wake in the night screaming about, who showed no remorse for his actions against his own son, who banished him, fully expecting him to fail at his quest.
He couldn’t face a world where Aang's laughter had vanished, the light behind his eyes replaced with the numb, cold look of horror's past.
When his warm ups are complete, he turns to Zuko, who joins him in instructing him in the advanced forms he had only barely mastered himself.
He pushes him hard in training. Though they have somewhat of a head start ever since the sun temple, he still has a lot to learn and little time to do it. By the end they are both breathing heavily and sweating, yet Aang’s still smiling.
“So, Sifu Hotman, how did I do?”
“Your posture could use some work, and your breathing is a little off mark, but you're really improving.”
His teaching technique is somewhere between Katara and Toph, definitely intense, but not devoid of softness and praise.
He smiles when he dismisses him from training, and Zuko can’t help but smile back.
He watches him bound towards the rest of the group, and he prays that the coming weeks will go smoothly, so he can watch his friend grow without the burden of his father breathing down his neck.