Forgive me, I'm a little rusty on his character an all, but.
As we see here, Itachi sealed Orochimaru with his Totsuka Sword. His Totsuka Sword is connected or merged with her Susanoo ability, which may sense seeing as how they are spirit weapons and Susanoo is connect to him.
Doing so gave him access to this ability.
The body replacement, because he know had orochimaru sealed within his being, and when something is seal within you, you have access to it's abilities.
EX.
Mito could use Kurama's sensory abilities, because she was an OP sealer.
JIncurki (SPCK) Naruto cloaks.
Sakura also Katsuyu has access to it too.
And we all know if Orochimaru is inside of you, you can use his Body replacement jutsu. As he is, with curse mark wielders.
Though Sasuke did absorb his essence, like Itachi did.
So basically, Itachi could've just lived if he want to. All he need to do was use orochimaru chakra and technique, and live.
But Sasuke needed his eyes, so he died. Noble Sacrifice .
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Itachi absorbed Orochimaru.Susanoo is a gigantic, humanoid being made of the user's chakra that surrounds them and fights on their behalf.
-Databook
Doing so gave him access to this ability.
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The body replacement, because he know had orochimaru sealed within his being, and when something is seal within you, you have access to it's abilities.
EX.
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And we all know if Orochimaru is inside of you, you can use his Body replacement jutsu. As he is, with curse mark wielders.
You must be registered for see images
You must be registered for see images
Though Sasuke did absorb his essence, like Itachi did.
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So basically, Itachi could've just lived if he want to. All he need to do was use orochimaru chakra and technique, and live.
But Sasuke needed his eyes, so he died. Noble Sacrifice .