He probably did not know the technique at that time.
it is also likely he could only revive people he killed himself. Remember the souls of the people he killed were inside that enma thing naraku summoned.
he killed him himself...
Why didn't he revive Jiraiya? Maybe it was too long ago since he killed him, and maybe it was too long ago when he learned that jutsu to revive Yahiko...
As to why he hadn't revived Yahiko my guess is he simply didn't knew he had the power. I know what you are saying 'cheap excuse'. But he clearly didn't, why else didn't he go six bodies of badass on the guys that ambushed him?. It was said that Life and Death was the seventh body's ability. The length of the death made it impossible for him to revive Yahiko later.
Last edited by Sevenheadedmirror; July 23, 2010 at 11:57 AM.
Well, I suppose he never used that thing before, as it required him to lose his life in the process. So, it was a once in a lifetime jutsu, and one that only works for recently deceased people.
He wouldn't revive Yahiko because he had a goal to fulfill before giving his life away. And when he decided to use it, it was too late for Yahiko.
I don't think it was a death jutsu like Shiki Fujin is. IIRC Konan said something like "Nagato, with your current chakra you'll- (die)", I can't be bothered looking for the chapter really. But it was appearant that he wouldn't normally die from it. How else would you explain him using the exact same jutsu to revive Asura Pain before the fight begun? He didn't die then. Why he didn't revive Yahiko is a huge plot hole to me, unless he was a total noob and didn't know the technique back then. Jiraiya could have been "too far away" or something, or been dead too long. And why Madara never used him before it was too late is a huge plot hole too.
Well, he didn't actually revive Asura Pain, so maybe that's why he didn't die when fixing it. In order to trully generate life, he likely would have to give up his own in exchange. At least that's what happened when he revived the people of Konoha. But otherwise that's one of those things we should throw back to Kishi's answer in a future Databook. I'm almost certain that reviving someone (not just fixing a "zombie" body) required his self-sacrifice.
And I don't think Nagato revived Yahiko because he didn't know he had the ability to do that. By the time he realized it, it was probably too late. It seems there's a time limit on using the jutsu on dead people, even he said it himself: "I still have time to revive all those people I killed. It's the least I could do." Something along those lines anyway.