Kataang - Revenge

If you wanted a cute and happy story, then this probably isn't the fan-fic you want to read.
3 years had gone by after... the incident and Aang was nowhere to be found. It was like he never existed, but was a faint memory in the background. Being a 16-year-old (Almost 17) he had matured a lot and was a lot more deadlier, not to mention handsome.
Eventually, after meticulous planning, Aang goes back to meet his friends, but not for the reason you think. You see, Aang had came back to finally plot his revenge against Katara. It's a long story. You're gonna have to read the rest of the story if you really want to find out why Aang wants vengeance on Katara so bad!

I don't own Avatar: The Last Airbender.
Trust me, if I did, there would be a lot more seasons.