I think your questions are not in the right context. Reviving someone means you bring them back to life and standing. It does not mean they won't die if they do something that can kill them.
First, Obito was in a certain death situation. It was clear that he had no life force left, and no chakra has well for having fought many days, controlling bijus, juubi, having juubi extracted, gedo mazou removed, and using Rinne tensei to revive Madara. See, Obito being still alive is one of the biggest mistakes Kishi has made in this series.
Next, to revive someone completely, you need to replenish their life force to the normal one. As we know, a Kage bushin only has half of the chakra that his original has molded before he was created. It is obvious that that half chakra is not enough to restore completely Obito's life force that was drained by the above-ementioned conditions.
Finally, notice that the reason Obito is going to die is the action he is going to take. If he were to just stand by or sleep like Guy Sensei, he wouldn't die for sure. So yes, Naruto power is consistent. It has not been proven that he can bring someone from the dead. Rather, he can either keep someone from dying, or put life in something that did not have it. I am pretty sure it is the same has Hashirama's lively wood dragon, except that Naruto seems to be able to put life in everything he want.
Naruto is using Yang Release, in other words he can breath life into shapes. (However, cannot create them from nothingness, that is Sasuke's power.) His power cannot bring someone back to life unless their bodies can take it or else they would need a new body. That is why Obito will die and his revival isn't permanent. |