The episode boasts with great action scenes. For one, there's Aang trying to run away from the Yu Yan archers, where we get to see a lot of awesome (albeit unrealistic) archery. And then there's Aang's and the Blue Spirit's escape from Zhao's fortress. The animation and cinematography during these scenes is very nicely done, and the action is very varied, ranging from sword fights, to bending, to bamboo ladders.
Along with the combat, we also get a great deal of stealth action. This is something completely new to 'Avatar', in which the action mainly consists of flashy fights and cool martial arts and bending. This, coupled with the great accompanying music from a Sunghi horn and chimes, makes for some interesting variety. The Blue Spirit himself is a very compelling character. Due to his (at first) unknown identity, people are left wondering what his motives are. Why is he helping the Avatar? How does he know where to find him? And his questionably methods only make his mystery greater.
When the Spirit is finally revealed to be Zuko, I have to admit that I was taken by surprise. Of the many possibilities of who this Blue Spirit might be, including a newly introduced character, Zuko is not a very unlikely candidate. His determination to win back his honor is so powerful that he undertakes great risks to assure this, and that includes disguising himself as a ninja and infiltrating Zhao's fortress. In terms of character motivation, it makes perfect sense.
Later on Aang tells Zuko of his Fire Nation friend Kuzon and wonder whether he and Zuko might become friends, and even though the prince attacks Aang and he flees, the Avatar's message seems to have made something in Zuko's mind click. And indeed, in another fabulous juxtaposition, Aang and Zuko both wonder about what might have been. The closing of this meeting is accompanied by slow and heavy music, one of the best mood-setters of the show.
'The Blue Spirit' was very intense, and mixed ample action with loads of character development, and it continues to ride on the high wave of quality that 'The Storm' has brought back.
Following "The Storm", a strong characterization episode, comes "The Blue Spirit", an episode with a good amount of action. The reason that I have not given this episode an "A" was for the beginning. The story starts out too slow for my taste. All in all, though, "The Blue Spirit" contains some intense action scenes that overcome the slow beginning of the episode.
This episode clearly demonstrates that Aang is able to learn from his mistakes. Aang is about to take his glider and fly to the medical institute, but he notices the sky is overcast and remembers how difficult it is to fly in a storm, therefore he decides to run. Though this might not seem significant it shows that Aang is a dynamic character.
Zuko, disguised as The Blue Spirit, seems to be one step ahead of the guards inside the fortress at all times. At one point he is even seen carrying a barrel of water to stop one of the guards. This appeared a little out of place to me considering that he didn't bring the barrel along with him. I doubt that he would have paused to take the time to fill up a barrel of water, especially since the place was crawling with guards.
Once Zuko releases the Avatar, a desperate escape attempt ensues. This is really the climax of the episode considering it is one of the only action scenes. A small point that I would really like to analyze is near the end of the escape attempt, when Zuko threatens to kill Aang rather than let Zhao deliver him to the Fire Lord. This is where we see Zhao's excessive pride come into play. He believes that he is in full control of the situation and therefore doesn't see the danger in allowing the Avatar to escape the walls.
What puzzled me during the next scene was why Zhao waited so long to have the archer fire at the Blue Spirit. He held off his attack until the Avatar was at a four road intersection a pretty long distance away from the Fortress giving Aang plenty of time to escape.
The most shocking moment of this episode comes when Aang unmasks the Blue Spirit only to reveal the face of Prince Zuko. This unmasking further reinforces what we already knew about Zuko's character. He will stop it nothing to restore his honor, even if it means delaying a Fire Nation victory. It amazes me how obsessed Zuko is with this seemingly impossible quest.
Perhaps the most symbolic moment of this episode occurs when Zuko returns to his ship. On the wall in his room is a large fire nation emblem. As Zuko goes to sleep he rolls over, turning his back on the Fire Nation.