WHO TOLD YOU THAT THIS WAS OKAY
Isn’t this rather out of character?
No. No it’s not. Because of this:
Do you see that?^
Because the rivalry wasn’t always there.
Because she was little once.
Because there was a time when she wasn’t a strategic genius and a firebending prodigy.
Because he didn’t always have to live under her shadow just ‘cause their scumbag of a father said so.
Because once they were just kids.
So no, dear, it’s not out of character. Not at all.
They were happy until zukos mother tricked ozai into thinking zuko was the child of the man she was engaged to before ozai basically kidnapped her. After that, ozai pressured and abused azula and abused zuko and forced the rivalry upon them. Because azula was 100% ozais child but for a while ozai thought that zuko wasn’t his. I mean, it still turned out that their mother faked the letter since she suspected ozai was reading her mail and she was right. He kept abusing zuko as a way to punish their mother.