Aang, at the start of the series

You are Aang and for you it felt like only a couple of hours passed since you found out you were the Avatar and you should be sent to another Air temple. But after two siblings from the water tribe discovered you in the iceberg you found out that 110 years passed since a great war between the fire nation and the other nations started. The two siblings were Sokka, who called himself a warrior, and Katara, who was the only waterbender, unlucky to not have a teacher, still both of them had great potential to help you stopping this war. Sokka was a really fit young man with decent muscles and Katara was one of the most beautiful and kind girls you could imagine. But after you and Katara had a little accident in an old fire navy ship the village sent you away. You were meditating in the middle of nowhere, your huge flying bison Appa sleeping right next to you. Your thoughts drift away as you think about the village, mostly the two siblings. They had a home, a family. Sokka has the most perfect sister but treated her not slightly as good as he should. "If I only could be like Sokka" you thaught. As soon as you open your eyes you get the shock of your life. Looking down you notice you are wearing water tribe clothes. You also notice that you have much more muscles and instead of a clean shaven head you now have some sort of ponytail. You realise you turned into Sokka! Your body is so much different than his. While your body is slim without much muscles, lighter to work better while airbending, Sokka had nice muscles because of his training and hunting. You also noticed something else, you lost your bending! But suddenly you notice that you can fight with your hands and other weapons much easier. You seem to aquire the abilities of those who you turn into. You quickly try out if you're able to turn and yes, only moments later you are back in your original body. You sit back down and continue to meditate, only minutes later you discover your next power, as you try to stand up you notice that you're in some kind of invisible ghost form while you're body is still sitting on the snow. You wonder if you can also possess somebody and since Appa is the onlyone near you fly straight into him. You world goes dark for a second before you open your eyes again and notice that you are huge. While you try to figure out how to handle 6 legs you see your original body waking standing up and petting you. "Good morning Appa, did you sleep well buddy?" He asks you. "Crazy" you think "it seems like my body goes on autopilot while I possess somebody." You think it's a wierd that you're Appa so you get out of him and back into your original body as fast as you can. There you notice that Appa doesn't seem to remember being possessed and that he seems to think that waking up was his own decision, coz he doesn't seem confused about that too, in addition to that you can also erase the memory of what you did, you can even replace them. You try to meditate one last time, feeling that there's still something new you haven't learned. As it turned out you are also able to not just leave your body to turn into your "possession-form", you are also able to turn your body into it, causing your original body to vanish. You think you finally know the most important things ...