Board Thread:Naruto Discussions/@comment-24165784-20151108230957/@comment-734582-20151114144551

Georgio722 wrote: But the Shinigami stays there until it seals a target right? I mean, there's no time limit as to how long the Shinigami or the RDS stays active right? Judging from Minato and Hiruzen's use, the Shinigami stays as long as the user can fight it's death. It seems to me that if a healthy person uses the Shinigami seal, it can be maintained for hours.

Secondly, i do not believe Madara using Izanagi is a proper comparison. Izanagi needs to activate first. It writes off all negative effects as a dream. i would expect that in order to make it work until after death, Madara had to seal away some of his chakra with it to fuel the technique. The price is paid up-front.

However, the Reaper Death Seal is clearly a thing of it's own. People that are caught in the Death Seal can not be put under Edo Tensei. So it seems to me that if the soul of someone put under Izanagi is stolen, Izanagi can not undo it. Bringing a person back from the dead is not that hard -Orochimaru says Edo Tensei is not difficult- and so when Izanagi triggers, it simply restores the body to its original state and pulls back the soul from the afterlife. But when the soul is with the Shinigami, it can't be pulled back. If Edo Tensei can't bring it back, Izanagi can't bring it back.

Therefore, Izanagi can not undo the sealing of a soul. Before that? sure. But if it activates after the sealing is complete then by the rules of Edo Tensei it can not be undone.