Fire. It burned within his core more than he would have liked to admit.
He could stop whenever he wanted to and he never let the flames get out of control.
It was something of practice. He would create the flame, let it breathe, give it life and let it grow. Like a playful child who just happened to have destructive tendencies.
But he could stop whenever he wanted. He could put out the fire, end the life of what he created and no one would ever be the wiser. He would brush the aside, bury them or send them down the stream and the others wouldn't even realize.
"What's that smell?", "What happened to my last shirt?", "Where did this black spot come from?"
"I don't know."
But then one day, something happened. He set the fire, he gave it life, he let it grow. He manipulated the flames and watched them dance, feeling the heat within and without. This was never what they taught him grow up. He was not to use life to create life. He was respect all things living, plants and animals.
But fire was living. It breathe. It danced. It was life. So when he was to put the fire out, he didn't. He let it grow, and grow and grow. He could not kill what he had given life to.
So as he watched the forest on fire, and his friends running around madly trying to put it out, he did nothing. This was his baby and it needed to grow. There was nothing they could do really, for it had gotten too big.
Eventually, they rode out on Appa and left the blazing orange life behind. Live, my love.
A/N: So, I made Aang a pyromaniac :D. Fun stuff ensue.