User blog comment:Omega natsu2/Chapter 373: Let Live Or Let Die, Predictions./@comment-24551285-20140224070236/@comment-24551285-20140225183444

Well...... Maybe I should emphasize more on the gedo rinne tensei no jutsu, but I think the jutsu work like this, the caster itself will die after using it unless it is from the uzumaki which have a strong life force, chakra and stamina to compensate. It requires enormous chakra consumption that can drain all the caster's chakra and stamina, forcing obito to inevitable death as noted by black zetsu.

Nagato revives all of the people he killed in konoha and there is a possibility that even jiraiya is revived. Firstly, Jiraiya is nagato's teacher and second, no people died in konoha due to not enough chakra for the jutsu or something and he might just have enough chakra to revive jiraiya. Due to jiraiya died a long time it might be harder to revive him as proven by obito who almost died when just reviving madara alone. Thus nagato is unsure if he succeeded or not that is why he said "I will go back to my master's place and watch over your story" before sealed by itachi.

Besides jiraiya might not be revived on the same spot he died as proven by madara. I suspect he might be revived on the spot where his severed hand is, and that is why kabuto cannot find anything related to jiraiya to revive him.

It would be a bit late to introduce a new character as the series is ending and kabuto with orochimaru dna is something karin can recognise that it is still kabuto. Thus I conclude my stand that jiraiya is the mysterious person in front of sasuke.

Of course I may most likely be wrong because the series has never fully explained anything about the gedo rinne tensei no jutsu, and there is no obvious hint that jiraiya survived.