Quote Originally Posted by Ryuchidori View Post
R we sure he is dead? Obito stated in his tree like statue, "he is stil alive on this day..." I can see, some people say, if he is not that, how could oro edo him, right? We dont know the whole secret behind edo-tense and maybe to lock someone else's soul in to a dead body, there isnt a must that soul must be in the other world?
No. We know enough to deduce that Hashirama is dead. Else he couldn't be ressurected in edo tensei.

If you take someones chakra and seal it in something, surely that might make it possible to bring out that person, but he will only be there for the time the amount of his chakra sealed will last. Like Minato or Kushina. Minato could only stay with naruto shortly since he had just sealed a bit of his own chakra inside naruto.