I don't love it when I feel compelled to address and refute the claim that an episode is filler because in so doing I have to talk about how it connects to later episodes and thus assure that it won't be spoiler free.
This episode establishes that Princess Azula is psychologically and socially maladjusted and genuinely finds things like human emotion and connection to be difficult to understand as anything more than a front (I know the YouTuber Hello Future Me suggested based on it that Azula suffered from Antisocial Personality Disorder but in real life you have to be 18 or over to be diagnosed therewith and besides it's unlikely that Azula would have felt remorse for insulting Tai-Li if she actually were an Antisocial Personality Disorder case.) Azula's mental issues from this episode are the set-up for her going mad in the series finale, so it actually does connect.
Likewise, Zuko being "angry at myself" for not knowing "the difference between right and wrong anymore" 1) suggests that he does know the difference, otherwise he wouldn't be so angry with himself and 2) establishes that he's continually conflicted about the side he's chosen setting up his eventual defection
Also, this is the episode which introduces Combustion Man to Team Avatar with the latter being specifically on the run from him for several later episodes.
So this episode isn't filler. That having been established, is it a good episode? Yes, it does a great job developing the villainous characters.
This episode establishes that Princess Azula is psychologically and socially maladjusted and genuinely finds things like human emotion and connection to be difficult to understand as anything more than a front (I know the YouTuber Hello Future Me suggested based on it that Azula suffered from Antisocial Personality Disorder but in real life you have to be 18 or over to be diagnosed therewith and besides it's unlikely that Azula would have felt remorse for insulting Tai-Li if she actually were an Antisocial Personality Disorder case.) Azula's mental issues from this episode are the set-up for her going mad in the series finale, so it actually does connect.
Likewise, Zuko being "angry at myself" for not knowing "the difference between right and wrong anymore" 1) suggests that he does know the difference, otherwise he wouldn't be so angry with himself and 2) establishes that he's continually conflicted about the side he's chosen setting up his eventual defection
Also, this is the episode which introduces Combustion Man to Team Avatar with the latter being specifically on the run from him for several later episodes.
So this episode isn't filler. That having been established, is it a good episode? Yes, it does a great job developing the villainous characters.