So the gaang is:
Master water bender,
The greatest earth-bender ever!
The last air bender/avatar/guy with cool hair
Warior/ boomerang guy
???????? (Fire bending teacher.)
I think we need an elite force that counter-acts the gaang.
Fire- azula
Water- this new villian (I think Katara's mother in joo-dee zombie form.)
Earth- Those two annoying guys that kidnaped toph.
Air- new avatar!
Just think,
That lightning blast almost killed him, the avatar cycle went on. Some-how a mystical bad guy did a rituel to make the avatar spirit come to him. Aang would still have his bending skills, I think any-one can do bending if they truly belive!!!!
Or roku comes back and does his super cool stuff to make aang fire benderized!