Perfection was who Azula was. It was what she strived for. When it wasn't perfect, then she made it perfect. It didn't explain why she was standing in front of Mai, who had just helped Zuko escape.
"What I don't understand is why. Why would you do it? You know the consequences." Azula made the last part as malicious as she could. She wanted to impress upon Mai the severity of what she had done, of the horrors that awaited her. She also wanted to help Mai repent. Perhaps she wanted to save her uncle. Mai's answer dashed this hope.
"I guess you don't know people as well as you think you do. You miscalculated. I love Zuko more than I fear you." Mai's face was perfectly calm, not betraying any emotion.
The answer was not what she had hoped. Her perfect friendship with Mai was revealed for what it truly was: fear. Azula did the only thing she had learned to do with imperfections. "No! You miscalculated! You should have feared me more!" As she prepared to destroy the imperfection named Mai, a hand struck her. She gasped.
Mai was always rebellious. But Ty Lee? Ty Lee who had feared her and did whatever she asked, even if it wasn't what she wanted? The guards rushed to her aid. "You're both fools!" She cried. "Put them somewhere were I'll never have to see their faces again and let them rot!"
There, she'd gotten rid of the imperfections in her world. But there was still one nagging one, the one that caused the first two imperfections. Her brother, Zuko. She went to the Western Air Temple for the sole purpose of killing him. She wanted to rid her world of the imperfection. But he survived.
She felt upset when her father wouldn't take her with him. After all, she had planned it. And she was the favored sibling. But then she learned she was perfect enough for Fire Lord. But she wasn't perfect enough to accompany her father.
Afterwards, she started realizing that nobody could be trusted. They'd all turn on her, one way or another. So she banished them, made sure they wouldn't hurt her. They'd never dare kill her. Afterwards, when Zuko came, she laughed. This was her chance, her chance to rid the world of the nagging imperfection.
She thought it would be easy. She threw everything she had at him. But he wouldn't bow down. He wouldn't die! He taunted her about him redirecting lightning. "I'll show you lightning!" She screeched. She started, then she noticed the filthy waterbending peasant. She smiled and directed the lightning at her. Zuko took the blow and her imperfection was gone! All she had to do now was teach the insolent peasant a lesson.
She was about to end her, when she couldn't move. She looked around and tried to fight the waterbender but she was chained down. But they will make me Firelord! Azula thought happily. Zuko is dead. But the filthy peasant revived him.
Azula started screaming, crying. For in the end, she wasn't perfect enough.