Zuko and Azula's Relationship
Unpopular opinion: most people agree that Azula’s downfall began with the betrayal of Mai and Ty Lee but I’m going to stand here and say it really started with the betrayal of Zuko during The Day of Black Sun.
Zuko and Azula have always had a bit of a troubled relationship but we see in Zuko Alone that they did get along somewhat as children. I don’t see Azula as being someone who’s needlessly cruel, ok maybe under the right circumstances, but she is someone who is willing to be cruel with reason. Have you ever been in a situation where you idolized someone and, once you got to know them better, you realized they were a disappointment? I bet that was the beginning of the breakdown of young Azula and Zuko’s relationship. Young Azula would have loved her doting, attentive big brother but as she surpassed him, she began to see he wasn’t as great as she’d originally though. Azula probably became bitter at Zuko for not being the excellent big brother she’d envisioned while, at the same time, building a lot of her self-confidence on being better than Zuko.