i think he gave him the power to get a rinnegan cause a rinnegan is made when you combine the power of uchiha and uzamaki cause that's how nagato got his rinnegan from madara

I also thinks its the Susanoo or at least something that could counter it. Given how smart Itachi was and how he said he hoped Naruto doesn't ever use it, I wouldn't be surprised that he may have seen the possibility of Sasuke turning into what he is now. He still loved his brother and may have felt that if Sasuke ended up the way he is now, this was the only way to end his brother's misery as well as save the villagem making Itachi's life more tragic.

I think its something to stop Madara Moon's Eye plan.

He likely left an imprint of himself behind, similar to the one the fourth left behind. It's probably set to activate once Sasuke uses Tsukuyomi on Naruto. He and Sasuke will have a conversation, Sasuke will reject Itachi's request and the Sasuke-Naruto smack down will commence.

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What convinces is not necessarily true, it is merely convincing.

I'm going to say it's that special soul sealing jutsu that the fourth Hokage made (the same one the third used against Orochimaru) I think Itachi learned it with his Sharingan and passed it to Naruto (it fits how the author likes to pass the important techniques of earlier generations to Naruto like Jiraiya and the fourth's giant frog summon, the fourth's rasengan, and Jiraiya's sage mode) all he needs now is the soul sealing jutsu and his set will be complete.

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All choices are made in fear,
What you fear more is the only difference.
Positive decisions are made in fear negative consequences,
Negitive decisions are made in fear of positive decisions not giving the outcome you want.
Embarrassment is the fear of people knowing your real thoughts.
Greed is the fear of having too little.

Demonblaze0's personal thoughts

I think the fact that Itachi is now walking about as a zombie completely rules out #4. If there is some hidden truth that Sasuke needs to know, Itachi could just show up and tell Sasuke himself instead of Kishimoto wasting the mysterious "power" on it.

So yeah, I'm still betting on it being an actual technique.

I think that it's a sort of genjutsu that will activate when naruto is fighting sasuke. When it activates Itachi will appear and tell his brother something about madara that will make sasuke turn against him. Then sasuke will tag along with naruto and he will die in the final battle with madara, using some kind of eye ability to make killing madara possible.

Itachi did something good?? Who knew!!

I think it's something to destroy the Sharingan. The only way to beat Sauske is to stop him from using the Sharingan techniques since they are so powerful and destructive. However, as the only Uchiha left, doing that would end the jutsu forever. That's why Itachi doesn't want it to come to that.

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ya know, after latest chap 550, turns out i was right, at least partially, about the "save Sasuke turn him good" stuff

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~Nothing is Eternal but Eternity~
Enjoy life as much as you can and do whatever you want, because it may be only one.

When the crow came out last chapter, I knew it was something to counter genjutsu. I'm curious about how it will work out.

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