Talk:Energybending/@comment-99.98.129.162-20120422000210

Aang used Energy-Bending because he is the Avatar and the Avatar knows all 4(5) types of bending. Before the World was split into regions of bending energy bending was common. Now that there are Kingdoms you can only have the bending of the Kingdom you were born in. So maybe the creation of a city for all has let people become enegy benders again because they arent born in a specific Kingdom. Aang could have remade Energy Bending by creating a new "Kingdom" without knowing it.

The only problem with this theory is Kyoshi Island. It might be still considered part of the Earth Kingdom though.