Once Sasuke's Chakra was exhausted, he could no longer suppress Orochimaru, whom he had absorbed and sealed inside himself.
An Eight-Headed Serpent burst from Sasuke's Cursed Seal, fangs bared and claws flailing. It was another of Orochimaru's forms.
This was the moment Itachi had been waiting for. Orochimaru had been waiting for it too.
The Eight-Headed Serpent was enormous, with eight heads and power greater than Manda's!
Orochimaru emerged from the mouth of one of its heads and grinned wildly at Itachi. He thought he was about to take Sasuke's body and kill Itachi as well!
But he knew nothing of the Mangekyō Sharingan's power! Worse, he had run into his destined nemesis: Itachi.
Perhaps Itachi's name said it all. A weasel was an animal that hunted snakes.
With Susanoo active, Itachi swung the Totsuka Blade in its right hand and severed all eight heads, one after another.
Then he activated the blade's Sealing power, swiftly dragging the Eight-Headed Serpent out of Sasuke's body.
"The Totsuka Blade? That's the Totsuka Blade! The sword I've been searching for was in your hands all along!"
Terror finally showed on Orochimaru's face, but he was powerless. He could only watch as the Eight-Headed Serpent was sealed inside the Sake Gourd hanging from the blade's hilt.
At the last moment, though, the last of his power became a small white snake and slipped away unnoticed.
It was much like Kaguya secretly giving birth to Black Zetsu when her own sons sealed her a thousand years ago.
Unfortunately for Orochimaru, his luck was terrible. Or perhaps, in front of Itachi and Sasuke, he had none at all. Before long, the surrounding flames of Amaterasu burned the little snake to death!
Having cleared away the last danger to Sasuke, Itachi finally looked relieved.
But he was