I like to think of it as "anime inspired" animation, but I see what you're saying. avatar was awesome! I love frozen and while Elsa is definitely the stronger Disney female heroine, Katara is the strongest female heroine.
I absolutely LOVED the first Avatar series and characters, but I feel like while the 2nd series had some cool points (especially spirit energy=nuclear power comcept) I just feel that NONE of the 2nd series characters stand as strong as the original characters. Katara and Soka were the best!!