Monstavatar: The Last Aircaster

It is a 2006-2010 tv series.
Cast
Mike Wazowski - Aang
Reggie (Free Birds) - Katara (to make a specifically role)
Twilight Sparkle - Sokka (to make a specifically role as well)
Olaf - Toph (to make a exciting appearance)
Kaos - Prince Zuko
Discord - Uncle Iroh