<p>Manga knowledge for Orochimaru on Itachi is basically just full knowledge at this point so now he knows exactly what he's dealing with instead of naively taking on the dude twice with the assumption he could handle anything he threw at him. Itachi is also on his last legs here already due to his sickness so the odds certainly seem to favor Orochimaru here. Orochimaru can handle anything 3T Itachi has and can use Oral Rebirth to counter Amaterasu. It basically boils down to whether or not Orochimaru can outlast Itachi and avoid Totsuka or if he can find an opening to attack Itachi from underground while he's in Susanoo. I don't think he can handle the likes of Itachi TBH.
Sure, he's immortal now,but he still can be sealed.
Giving Oro full knowledge w/o prep, won't do any good, because he has nothing to counter Visual Genjutsu.
Oro had knowledge of the Sharingan and Genjutsu on the series, yet he still was caught in a Random Genjutsu :<i>v</i>
He should still be afraid of Itachi. But Kusanagi is a very straight forword attack, and sharingan is great to dodge straight forward attacks, if he sees a sword coming at him, Itachi should be able to dodge it. databook said Kusanagi-like blades, because they look like Kusanagi but they're not the Legendary Sword, because tehy can't be 10000 copies of Kusanagi, otherwise it would be the most common sword in Narutoverse, no Legendary.
I think they can't attack from multiple directions, they are somehow attached to Oro's mouth, if they could attack from all directions they would've surround NK4. Even so, if Tsunade could crack Susano'o, copies of Kusanagi or not, hundreds of blades should be able to as well, with ease.
Then again, perhaps its a special ability of Kusanagi to be reproducible by the one who wields it, seeing as it represents surpassing physical limits (which should include numbers). Kusanagi failed to put a scratch on KN-4.
Susano is mode durable than that. I'd say stamina would be the deciding factor. And Prime Itachi doesn't have sickness I think. I'd say Itachi wins high difficulty.
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