Since the juubi is here, the fox existence for the frist time in his life will be at risk.
As if the fox losses the juubi will simply aborb him and the fox as we know it wont exist. Same goes for all the tailed beasts.
I think the 8 and 9 tails battle will be something we have never seen before they will be working together like in 4 man shinobi team. Well for them its a 2 man.
And if that fail there is always the fox doubling is chakra by going sage mode with naruto, hey hey. Naruto would have to absorb the same amount of natural energy as the combined chakra they have(naruto + fox).
Not sure how long that will take or even if there's enough natural energy out there lol.
Anyway just really excited about the upcoming chapters. In particular the fox, he had a special relationship it seems with the so6p. The fox might feel he has duty to do this for naruto to finsh the so6p's work. Once and for all. and tailed beasts(and therefore the juubi) will be finally no more.
The fox saving the day, ending conflict among shinobi over the tailed beast's power, I think is the best and coolest ending kishi could do. That's just me anyway.