*sigh* There are a billion holes in the "Zuko is not evil" theory.
1) People claim Zuko conspired with Iroh and created this plan where they would trick Azula into thinking he was helping her - First, this could very well be possible IF this wasn't a TV show. In shows, things don't happen off screen, all that matters is what's on screen. Some people may disagree, but in most cases this is true, I mean, come on, if something that important were going to happen, they'd at least hint it some what. They wouldn't end the season without you being even vaguely aware of something that big. Second, Zuko told Azula that he felt he betrayed Iroh. Only a pathalogical liar would have the nerve to bring up the very subject they're lieing about, and while Zuko is confused he's not a pathological liar like his sister.
2) Brainwashing - once again, something that big can't just be left up to speculation, it has to at least be hinted, that's like saying they brainwashed Iroh. Do you have any proof? No. That's just pure guessing in a feeble attempt to understand exactly why Zuko acted the way he did.
Personally, I don't think Zuko is evil, and I bet even the??some of people who think he's going to be a villian for good now, don't think he's evil, he's just confused. Have you not been watching recently? The whole angel(Iroh)/devil(Azula) thing they've??had going on since episode 18. First of all, the avatar stung his pride??with the "Saving you, that's what." comment;??he wasn't exactly happy to see him, and while people say??he's been through a lot of??character development, which he has, no amount of character development will??be able to??make up for the fact that he's only human. How would you have acted if you felt someone close to??you??betrayed you,??then someone else offers you a chance to redeem yourself and gain the very thing you've been searching for??for three years,??not to mention that very??"thing" just wounded your pride (Zuko is very proud) and has been the reason you've not been able to return home? Can??you honestly say that you would have turned the other cheek, forgotten everything that had??happened,??and joined your "enemy"? I know I wouldn't have, something like that would have just been too??good to pass up.
Just to summarize this:??Zuko couldn't have been brainwashed because that's??pure guessing, there's no proof that suggests that he was brainwashed, that's like saying my neighbors were brainwashed,??you don't know if they were, there's a billion different possibilities when you make up random guesses that have little to no proof. There are thousands of holes in the "Zuko is not evil" theory, but then, that's not an appropriate title because no matter what, we know Zuko isn't "evil", whatever, you know what??I'm talking about. If you were in Zuko's place what would you have done? Forgiven the avatar for everything he's done to you and give up you honor, throne and country forever, or bring him down and redeem yourself and regain everything you lost. ZUKO IS ONLY HUMAN! NOT EVIL!