A/N: I'm back and bearing fic!
Soulmates aren't supposed to break up.
From the moment he awakened from the iceberg in Katara's arms, he'd sensed that they were meant to be together. They could repopulate the Air Nomads, see the whole world, go penguin-sledding until they were thoroughly sick of it. She's the prettiest, kindest, (only) girl for the job.
But she'd patted him on the head and denied everything, stood cold and languid as a statue when he kissed her before the invasion, said point-blank that she was confused on Ember Island, and finally dealt the damning blow.
{I'm so sorry Aang, you're such a nice guy, this isn't your fault at all, I really do love you but not that way, I'm sorry I just can't-}
Because he didn't capture her heart, in the end. Zuko did.
Hot-tempered, uptight, arrogant Zuko, who doesn't quite know how to smile yet, flinches if someone touches him unexpectedly.
{Zuko, who helped her find her mother's killer, took a bolt of lightning for her, left his home and honor to throw himself at the mercy of his former enemies, makes her laugh with jokes that don't even have punchlines. That Zuko.}
He wants to be happy for them- really, he does, he'd be a massive hypocrite if he didn't. The monks had preached that one must never harbor vengeance in his heart; Guru Pathik said that in order to become a true avatar, he must detach from the rest of the world. And most of all, he wants Katara to be happy. It just hurts, brutally, to accept that she will never be happy with him.
Soulmates aren't supposed to break up.
But destiny is a fickle mistress.