Um, it could have been pain....I mean truthfully pain had a choice and naruto make him make the "right" choice. I mean think about it. Nagato could have probably killed naruto which would have destroyed the world (since naruto wouldnt be here to fight kaguya). Then there is minato who could have decidedto not seal Kurama in naruto so kaguya would have probably been summoned faster before naruto could have developed to fight her.
Rhen there is naruto who could have decided to join obito when he was offered after nejis death. That page (s) are very vague amd could apply to anyone of jariyas pupils.