This is a sad story at least by my opinion. Whether you readers find it sad or not is up to you. I don't own avatar.
I saw blood. Lots of blood. It fell onto the ground like rain and soaked it in a demonic crimson. The sight is horrifying for most sane people. To me, it brings peace to my heart that's been twisted by endless hatred .
The red clothed people are scurrying about. Some are running in fear while some are assaulting me as I tower well above them. My new body protects me from the attacks of the people as I assault them back with my hatred.
My new body leaves deep marks in the ground where it walks. Marks that only a monster can make. The marks are lined with a cold, clear, solid substance that comes from my heart. I continue leaving such marks as I chase those that have made me feel fear for so long.
Those that believe beauty is only skin deep are correct. On the outside I was rather lovely, on the inside I'm a monster twisted by hatred. The monster has been growing inside me since the day I lost my mother.
I turned to the monster for protection as it fed off of the fear and hatred that I've felt endlessly for years. Those red clothed people caused me so much pain, but I hide it so well that most people didn't noticed.
Now the monster as grown enough to take over my body and is now guiding me as I hunt the red clothed people. My new body is crafted from the substance that lines my marks on the ground, a physical form of the monster made of my hatred.
The red clothed people are lying everywhere covered in their disgusting fluid that flowed through them. Their numbers are lowing, but it doesn't stop the wave of hatred flowing over my body like a flood.
The chase is coming to an end, but the hatred in me doesn't stop flowing. As long as the monster in me is still feeding of my hatred I will never disappear. I will continue to hunt the red clothed people the caused my hatred.
My monster lets me feel the piece I've felt so long. I never want him to disappear.
That's all. It's mainly about Katara turning into a monster from her hatred of the Firebenders since the killed her mother.