Overall, i think that the ender dragon plays a huge part in the game because you have to defeat it to finish the game because you need to defeat it to win the game. The boss fight would be a lot better if you rode on another dragon while defeating him. This Dragon would be the aether dragon. it would be found in an aether realm with nothing but the aether dragon floating in front of you. unlike in the aether mod, it would be one giant island similar to the end realm. the portal would be made of gold blocks and lit with a diamond. it is so hard to make because it will let you gain access to the aether dragon which will help you fight the ender dragon. if you approach him, he will say that he wants to see if you are worthy of his help. it will behave similar to the ender dragon without any healing. he does more damage but he will stop at half health. he will then say "Meet me in the end" and fly off. when you enter the end, you will spawn near the aether dragon. and if you right click on him, you will get on the aether dragon and he will take off. the battle would be just as normal except for the fact that you are flying on a dragon and can make the dragon breathe blue fire if you left click with a diamond in your hand. this is what my idea would be, hope you enjoy it.