Am I the only one who thinks that it is completely illogical that one can release himself from edo tensei with just performing the right seals? it would mean that you could just edo everyone and tell them the seals to release the jutsu. don't tell me that it is a secret jutsu and that only few know how to do it!! Tobirama knew how to do it (of course not perfect), oro, Kabuto and Tobi. i generally think that edo tensei is too strong to fit into the story. a jutsu as powerful as edo tensei makes the whole story illogical, but I accepted it because I like the idea of kishi to show us all the characters of the past and the legends in action, so it was necessary to disturb the logic of the story a little bit and create a jutsu like this. but now he went too far.
if the dead can release themselves from the jutsu it is just as good as gedo rinne tensei (of course except the fact that you need a sacrifice for the jutsu, but you could take enemies or people who are deadly ill or something). It is great that madara remains in the story but kishi could have done this by a different way. Perhaps short before his death, when he saw that there was no escape, Kabuto could have taken all his remaining strength to send all his chakra into madara to make his body live for one more hour or something like that. with a method like this, madara could have ended his fight with the kages or whoever and the story would make at least a bit sense.
if the dead can release themselves from the jutsu it is just as good as gedo rinne tensei (of course except the fact that you need a sacrifice for the jutsu, but you could take enemies or people who are deadly ill or something). It is great that madara remains in the story but kishi could have done this by a different way. Perhaps short before his death, when he saw that there was no escape, Kabuto could have taken all his remaining strength to send all his chakra into madara to make his body live for one more hour or something like that. with a method like this, madara could have ended his fight with the kages or whoever and the story would make at least a bit sense.
