Zuko is two when Azula is born, and as a two year old he has no use for her. All she does is sleep or eat, and rarely cries but when she does it is loud and it scares him. Sometimes he can't help crying too, and he feels ashamed when their mother wraps him in her robes to soothe him. It is natural for a newborn to cry but for a growing prince of the Fire Nation it is disgraceful. He knows it as she dries his eyes when Azula has long since stopped.

Zuko is four when Azula is two, and as a four year old he finds her an annoyance. She does more than before, just beginning to realize she can do things he can't and shadows his movements to test their differences. Zuko would rather tag along behind Lu Ten but their father has declined their last few invitations. Zuko doesn't know why things are this way but he feels lonelier for it, and Azula is no comfort because she is too young to miss them. Instead she digs her fist against her brother's side to get his attention, delighting in her power when Zuko squirms but doesn't strike back.

Zuko is nine when Azula is seven, and as a nine year old he begins to resent her. Father's favor shows in everything, when he enrolls her in the Academy and she brings home playmates as the first spoils of her victory. Azula offers him a place but only if he plays by her rules. He would rather be alone than with his little sister and the others, more her friends than his. It is the first lesson Zuko forgets to learn about human nature as he walks away, Mai's eyes following after him and Azula glaring in return.

Zuko is eleven when Azula is nine, and as an eleven year old he admits he fears her. They are always made to compete, but never allowed to fight each other. It is the one law their mother holds absolute over their father. However, that doesn't stop Azula from hurting Zuko in other ways. Every word she designs to cut beneath skin and leave no evidence. When their mother vanishes Azula still hides every wound she inflicts, but it is merely because she has grown to appreciate the skill it takes.

Zuko is thirteen when he is banished. He doesn't think about Azula while he looks for the Avatar, and he is neither disappointed nor relieved that she doesn't make an effort to look for him.

Zuko is sixteen when Azula is fourteen, and as a fugitive he becomes her enemy. Everything he strived for in capturing the Avatar she turns on him—effortlessly, mercilessly. Azula will always turn on him. Sometimes he thinks she is the counteracting weight of his punishment, a pendulum swinging to return every cruelty those he pursued accused him of doing. He hates her. But when she stops hunting him and embraces Zuko like family he realizes it's only because he hates himself.

Zuko is seventeen when Azula is fifteen, and as Fire Lord he must decide her fate. She is the last figure of a hundred year old regime of fear, but she is also his blood. And no matter how different she is from him, he cannot separate her. Zuko has no real memory of the world where he existed and she didn't, so although he knows it once was, the fact does not comfort him. He has never been close to her but now, with the ruins of an empire between them, she has become impossibly far away. And he wonders if any amount of time could heal that.