The way any extremely powerful foe gets defeated in a Shounen Manga:
1. Either an extremely powerful attack that takes the energy of many people that and is hax AF
2. Or the enemy allows his arrogance to be his downfall.
I hope Obito whoops some ass before he goes out though.
Don't know don't really care, Obito will die in the end anyway no matter how powerful he'll become in the next few chapters.
All the crimes he's committed in his life time won't be forgiven so his only way to repent is by dying.