Aang nods, and allows the puzzle pieces to come to rest on the palm of his hand. Each one is flipped so that the picture side is down revealing hand written numbers on the back of each piece.

"It's both, really. If you're born a bender, then you bend the element of you're most spiritually connected to. People from one of the Earth Kingdoms are earthbenders, firebenders come from the Fire Nation, and then there's the two Water Tribes."

Aang skips over the Air Nomads, for...reasons, opting instead to look for the boxes labelled with the same numbers as the puzzle pieces.

"Avatars reincarnate. When I die I'll be reborn as Korra, just like I'm Avatar Roku reborn."