Iroh angst yay. Set at various points.
He fails his brother first of all.
Of the two of them, Iroh's star had shone the brightest in all things. The flames bent at the merest application of his will. His tutors had hovered between delighted and astounded at his diligence even in those few areas of study he did not enjoy. Genius came naturally to Iroh.
All Ozai ever had on his brother was his height.
Iroh never stopped, never bothered to take the time to bond with his younger sibling. There was always work to do, music to practice, bending routines to master. And so the distance between the siblings grew, Ozai always vainly attempting to match his brother (he had long since abandoned any attempts to outpace him), until Iroh no longer knew Ozai.
But he had more important matters to attend to than visiting Ember Island with his brother.
He makes his first mistake when he is forty years old.
General Iroh. The Dragon of the West. He has blazed a trail across the Earth Kingdom, doing in two years what his predecessor could not do in twenty. And now his great force lays siege to the city of Ba Sing Se, the single largest metropolis in the world.
Unbeatable, the propaganda calls him, and so far he has proven it right. Unstoppable. A genius on the field of battle, incapable of error. He will make a glorious Fire Lord.
His first mistake is made when he starts to believe his own legend.
He fails his son second.
The Outer Wall had fallen to the war machines of the Fire Nation, and, in his hubris, General Iroh believes he has won. He sends his army pouring through the crack in the wall, heading straight for Ba Sing Se.
Iroh recalls thinking that it will have to change its name, just before the ambush is sprung.
He fails his father third.
His spirit is broken. The Earth Kingdom orders a massive counter-attack.
The legendary Dragon of the West is no longer sure he cares. He directs his troops as best he can, but his manoeuvres are pedestrian, and easily thwarted.
(Later, he is informed that once he left his army, a force from the south caught his men between two Earth Kingdom armies. It was a massacre)
His second mistake is made when he is forty-one. His brother's wife has vanished. His father is dead. His brother is Lord.
These three facts assault him the instant he returns home, hundreds of years older than when he left.
And there is his nephew, so lost, so alone, and some selfish corner of his heart cries go to him, take care of him. Here, here is the boy that will act as your son, fill the hole in your chest, so you do not have to grieve any more.
So he does, not strong enough not to, the thought barely crossing his mind that Zuko was not the only one to lose a mother.
(Azula had always been her father's daughter first and foremost, in any case)
He fails his sister-in-law fourth.
Ursa had, for all her faults, loved her son fiercely, and Iroh had promised her absence that no harm would come to Zuko.
Another promise broken, and all he can do is follow the boy into exile. He gathers the best men he can- loyal to his name, for the most part- and joins his nephew in his hunt for a ghost.
Two years, maybe. Two years at most, and then his brother will relent, and allow his son home.
The next years were spent making several mistakes regarding his nephew. Chief among them was the decision he made not to utter three words. He should have said it. He wanted to say it. Zuko needed, needed to hear it. But Zuko wouldn't want to hear it. And so he didn't. The closest he ever got was saying he thought of Zuko as a son.
(It was true enough, but he had forgotten what Zuko associated fathers with)
It was three years before he realised the extent to which he had failed his niece.
She appeared, and perhaps the years away had dulled his memory of her, or perhaps she had gotten worse in the years at home, but Iroh couldn't remember her being so brilliant and simultaneously so utterly, completely broken.
He cannot look her in the eye.
It was easier to imagine that she couldn't be helped, could never have been helped, and to his eternal shame it was easier to tell her own brother he had to kill her than admit the possibility that maybe, maybe, if Iroh had taken the time to talk to her, to try, not to leave her to Ozai (and what had happened to his brother, while he hadn't been looking? When had he started to look at everything as a weapon?), then she might have grown up knowing more than the idea that the world is divided into those that cause pain and those that receive it.
But he had been blind. And now the entire family would pay the price for his ineptitude.
He fails the last member of his family.
Whatever he had offered his nephew, it hadn't been enough, never been enough.
Maybe he had asked too much of the boy.
Regardless, Zuko had chosen against him, and Iroh realises finally that Zuko is not and never will be Lu Ten. And Iroh should never have tried to be the boy's father.
(No matter how badly he needed one)
He is imprisoned, where he can no longer make mistakes. There isn't anyone left to fail.
Another man would have broken by now. Would have cracked.
Iroh doesn't. He doesn't have the right to.
Breaking would leave everyone else to shoulder the burden from his mistakes, and he still has some strength left in his shoulders. He will not sit aside. No matter how angry he is at Zuko at the moment.
(It's not as angry as he is at himself)
Maybe, if he escapes, he will make more mistakes. Maybe that is his curse.
Or maybe he can try to set things right. Or at least hurl himself between the lightning and the worthy man he knows his nephew will grow up to be.
So it is decided.
There is still much for him to do. And he can afford no more mistakes.