I rewatched The Avatar and the Fire Lord a few days ago, and god, what a good episode. Revealing that Zuko is a descendant of both Sozin and Roku was a genius move (and that's not even getting into the Zuko/Aang parallels of it all). But there's something the show doesn't seem to think of, and that I haven't seen anyone in the fandom discuss either — the fact that Zuko isn't the only one descendant from both these men. Azula is, too.
The conclusion of this story that Iroh presents to Zuko at the end of the episode is that he alone — because of his lineage from both men the war was started from — is uniquely capable of cleansing the sins of his family and the fire nation and bringing peace to the world. But, the thing is, there's two sides of this conflict, and therefor two sides to its legacy. The external and the personal. The legacy of the external is the war, but the legacy of the personal is the sibling rivalries that kept repeating through generations of the royal family.
Though Roku and Sozin were not actually related, they were childhood friends as close as siblings and fucking shared a birthday, so the symbolism works. We know very little about Azulon's childhood or if he even had any direct sibling rivalries like this at all, but from what I can find on his wiki page, we know that Sozin favoured him over "other family" (I'm assuming his siblings). What we know very well, however, is what happened in the next generation between Iroh and Ozai. We know Azulon favoured Iroh over Ozai, and that this likely is the initial source of their hatred for each other, which resulted in perhaps the worst sibling rivalry of them all (what with the indirect patricide and throne stealing).
Then we go on to Zuko and Azula, whose upbringing kept going in the same patterns, but the key difference is them being the first ones to both be descendant from the men who started it all. If Zuko having this lineage makes him uniquely capable of ending the cycle of war in his country and restoring balance to the world, shouldn't that mean that both he and Azula having this lineage makes them uniquely capable of ending the cycle of brutal sibling rivalries and restoring balance to their family?
This conclusion I've presented seems to fit perfectly with the lesson Aang draws from the same story as well:
"Roku was just as much Fire Nation as Sozin was, right? If anything, their story proves that anyone's capable of great good and great evil. Everyone, even the Fire Lord and the Fire Nation, have to be treated like they're worth giving a chance."
I know this is supposed to be foreshadowing to Aang refusing to kill Ozai later, but I can't help but think it's even more applicable to fourteen year old Azula. It's really so ironic that the show runners thought Azula deserved what she got when their own show seems to be telling them that Zuko mending his relationship with her is what he ultimately should've done.
But, then again... that does sort of make her the perfect tragedy.
