[X] Iroh. Coward. General. Prince. Once, he was the favoured heir, a legendary firebender, the greatest hero the Fire Nation had known since Sozin—now he's a pathetic, doddering fool who thinks he can make everything right with tears and tea. How did he fall so far? How can he possibly think he's still able to rise?
Azula has always struck me as jealous without ever consciously recognizing her own jealousy, like at some point she tried and failed to identify the feeling, skimming right past the correct answer, and then casually disregarded it because she worked herself around to the idea that she had nothing to be jealous of because she was the best.
While Iroh is the natural forward beat here, and I believe the outcome will be interesting, I suspect the most powerful outcome will probably result from Ursa, since it would force Azula to confront the fact that she actually is jealous of Zuko, both for having the spine to stand up to daddy and thus ensure the old man doesn't 'love' him, and for being the one Ursa and everyone else seems to love more than her.
Her obsession with loyalty likely even springs from viewing the killing of Azulon as the ultimate test of loyalty. She's constantly trying to manufacture and test-through-personal-sacrifice a relationship like the one she saw between Ursa and Zuko.