I love how, in two lines of dialogue, we have their sibling relationship. Constantly fighting and ready to blow each other to bits. Yet when he sees his little sister in trouble, he just wants to rush in and help. But then she saves herself by her own cunning, and he's reminded again of how powerful and dangerous she is, and that letting her fall would bring them one step closer to Ozai's defeat. That, my friends, is good writing.