I have ended the Enderdragon, got the Enderdragon Egg, made my village, mastered the overworld and have been wondering. I feel like taking the Enderdragon on again. Is this even possible without starting the world over?
No, there is not a current method to reset the end and beat the EnderDragon as many times as you want. Unfortunately, you'll just have to create a new world and go through the process again. I believe there is a method to do this on PC, but with the limitations of file editing on consoles, there is no method for resetting the end on your Xbox.