In one of the episodes I saw he transformed into a past avatar and had Hokage level powers over all 4 elements. Think it was a one time use only thing during a special positioning of the sun or something though.

And they have that one fire nation girl that can close your chi (chakra) by hitting your pressure points (tenektsu) using a hand to hand combat style (gentle fist) so your body becomes almost paralyzed and you can't use any bending (jutsu).

Coincidence?

Overall I think it's a pretty good show, even if it is aimed at a lower age group, and it's like the only nickelodeon show I actually watch besides some of the anime they've had.