Board Thread:Naruto Discussions/@comment-26993711-20160319001508/@comment-27660682-20160320064217

Nagato showed no such ability. He was looking at itachi's right eye and assumed it was amatersau from the bleeding but he was wrong, it was just kotoamatsukami working on itachi. Also, obito could have just prepped izanagi beforehand. Izanagi is one of the most inconsistent jutsu in the series, but in Danzo's use he would prep the hand signs, then after that each eye would remain open for 60 seconds protect ing from any attack in that time frame. Obito was shocked when he saw sasuke's eye changed, so there was no way he was focused enough to activate izanagi on that spot that fast, not even Danzo could do that, he just prepped izanagi before hand. But then again as I said, izanagi is inconsistent so the best answer for obito's survival was having his hidden eye have a prepped izanagi,  or it wss simply plot.