i haven´t been really focused on Naruto´s manga for a while but isn´t the impure ress a jutsu supposed to be ressurecting all the great ninjas? if that is the case why haven´t we seen guys like jiraya, orochi, and minato in battle? I believe Minato still has a role to play in this story and i hope we can see more from him soon.
you need there dna and there soul cant be sealed
so the 1st, 2nd,3rd, and 4th hokages cant be
summoned because there souls are sealed with the
shinigami soul sealing teck. oro souls is sealed
by itachi. and kabuto said he couldnt get to
jirayas body to get dna because it was at the
depths of the ocean
yeah. they need to have the dna, and jiraya was in
the bottom of the sea. so kabuto could not get to
him, and both orochimaru's and minatos souls
were sealed, orochimaru by itatchi and minato
sealed himself inside naruto.