system
A chat on subreddit /r/NoStupidQuestions
human
Clear good &amp; evil is not the same as a classic Good Guy vs Bad Guy.

Rather, each episode clearly shows some acts of good and some of evil.  It isn't subtle.  There's a "the right thing" and a "the wrong thing" constantly.

What it does do is show that sometimes a good person can do a bad thing, and vice versa.  As well as Zuko maturing over the series alongside the group of protaganists.
gpt
I think redemption arcs are often a good starter for moral greyness in kids shows, and they are seemingly common. I remember growing up as a little kid watching the first Pokémon movie and enjoying the progression from “Mewtwo is genocidal” to “Mewtwo lost and became good.” 


Avatar was great at showing a redemption arc and explicitly showing how and why people struggle to change. You’re absolutely right about there being a well-defined good and bad in the show, although the ending of it made an exception. When Aang had “good people” telling him to kill Ozai, yet felt that doing so was morally wrong, I think that some could argue that at that point the show portrayed true moral greyness. But, to counter my own counterpoint, the show still ended with Aang not changing from a “morally good” position by keeping Ozai alive. He just found a middle path by taking away Ozai’s bending that allowed him to stick with it, effectively circling back to non-ambiguous moral standards. Effectively the ending of show probably made a sense of moral greyness more memorable for most people.

Anyways that wall of text is proof that I need to lay off the coffee.