Board Thread:Theories and Speculation/@comment-26005711-20150719134117/@comment-3568954-20150721181709

When Nagato used Rinne Tensei

It was implied that he would die solely because he only had a small amount of chakra left. but now it isn't that way it was mentioned by Madara that using Rinne Tensei always results in the casters death.

Obito is different as he had black zetsu attached to his body and then when Black Zetsu stole Kurama from Minato and then entered Obito's body kurama's chakra rejuvenated him so that he would no longer need to worry about dying because of it