First off, Uncle Iroh was Toph's old friend? That was weird. Also, when Katara was with Zuko they started bonding, or something. Like right after that second Aang and Uncle Iroh broke in. Lastly, when Aang was about ready to destroy the whole army fighting him, Azula struck lightning at him and he was down. Then, Uncle Iroh traded the army while Katara escaped with Aang and Iroh was arrested. Due to that, the Fire Nation took over Ba Sing Se and Aang almost died, and that was the Season Finale of Season 2. That is one good thing about Avatar. Everything is unexpected. I like that. I thought the whole episode was pretty good.
Overall, there was not anything bad. A+