"Can you escape? Genjutsu Binding!" Itachi didn't need to worry about his own life at all; he was completely pushing himself to the limits in battle. After all, he knew he would die soon and had no reason to hold back. In the space between life and death, Itachi's combat strength surged to a hundred and twenty percent for a short period.
"It's useless. Although my soul is heavily damaged, the existence of the Sharingan helps compensate!" Orochimaru's corrupted Sharingan spun, clearly readying to break free from the illusion.
"Heh, Tsukuyomi." Itachi coughed; though his body was crumbling, his ocular power remained. He had chosen to conserve more of his ocular power for Sasuke. However, facing the overwhelmingly strong Orochimaru, he had no choice. Fortunately, Orochimaru didn't have a nearby corpse to use for Edo Tensei. Otherwise, Itachi would be in trouble.
"Damn it." Orochimaru understood that the current Tsukuyomi was vastly different from before. The Tsukuyomi Itachi used on Sasuke earlier had been like a tutorial on how to use the Tsukuyomi, both in casting and countering it. It hadn't caused Sasuke any psychological trauma. However, the situation was different now. The Tsukuyomi that Itachi subjected Orochimaru to was a genuine mental assault.
Itachi's full-powered Tsukuyomi was difficult for Orochimaru, even with the Sharingan. If Orochimaru could repair his damaged soul, he wouldn't need the Sharingan to resist Tsukuyomi. Unfortunately, now that he had pushed Sasuke's consciousness down and incurred further damage to his own soul, even the Sharingan wouldn't keep him from collapsing due to the mental attack.
"Damn you, Itachi. I'll endure. You'll be dead soon, and your eyes will belong to me." Orochimaru, within the Tsukuyomi space, was bound to a cross, continuously attacked by Itachi's katana.
If Itachi had used this technique on Sasuke, Sasuke would have been killed instantly. Remember that even back when Kakashi, who were far stronger than Sasuke at the time and possessed the 3-tomoe Sharingan, had been defeated instantly. Orochimaru was no exception.
"You won't get that chance. No matter how much time passes in this realm, it's only a second in the outside world. When this Tsukuyomi ends, your soul will suffer tremendous trauma. When it returns to your body, there'll be an instant of deadlock, and then you'll die without a doubt." Itachi snorted. He had over three days' worth of time within the Tsukuyomi space, so he didn't mind wasting some time verbally sparring with Orochimaru.
Three days passed quickly. Orochimaru endured torment within the space for three days and nights, sustaining severe mental trauma. Nonetheless, he held on; after all, Orochimaru was known for his tenacious survival instinct. He wouldn't be killed easily.
"Be sealed forever, Orochimaru." After exiting the Tsukuyomi, Itachi immediately aimed the Sword of Totsuka at the dazed Orochimaru, who had just suffered a mental attack, and thrust.
"Damn it, am I about to be sealed by the Sword of Totsuka? Damn it, I underestimated the Mangekyou Sharingan too much. I never thought it would possess such powerful techniques." Orochimaru was extremely anxious, seeing himself about to be sealed. He was reluctant to give up the body he had acquired, but Orochimaru was still ruthless; he understood that hesitation could lead to his downfall.
Before the Sword of Totsuka could pierce through his heart, Orochimaru employed a secret technique, transferring his soul to a white snake. He escaped Sasuke's body in an instant and simultaneously summoned a giant snake, which swallowed the white snake. Then, using the Reverse Summoning Jutsu, Orochimaru sent the giant snake back. He narrowly dodged the fatal blow, escaping the sealing.
"It doesn't matter. Now that Orochimaru has escaped, I can remove the cursed mark from Sasuke." Itachi sighed. Indeed, a centipede will die but never fall. Orochimaru wasn't easy to kill. Itachi had a feeling that even though Orochimaru failed to take Sasuke's body this time and fled, Orochimaru's subsequent actions would undoubtedly become more bizarre. His rationality told him that this feeling was absurd.
Even if Orochimaru managed to find a new host body after losing his original one, his soul would still deteriorate upon possession. In the future, even if Sasuke gained the Mangekyou Sharingan, he wouldn't need to fear Orochimaru. However, there was a strange feeling that Orochimaru, after escaping this time, might encounter some kind of opportunity. Maybe due to losing in one direction but gaining in another. Orochimaru first gained Sasuke's body, then lost it. But in his loss, he might find an opportunity for his soul to recover.
Itachi was well aware that he had defeated Orochimaru solely because of Orochimaru's damaged soul issues. However, he had a feeling that Orochimaru's escape this time might lead to some kind of fortuitous encounter, a chance to turn the tide. Orochimaru had first acquired Sasuke's body and then lost it. In his losses, he might find a new opportunity. Perhaps this opportunity could lead to the restoration of his soul.
Itachi knew that if Orochimaru's soul hadn't been damaged, even in his prime, Itachi wouldn't have been Orochimaru's match, even if Sasuke activated the Mangekyou Sharingan. If Orochimaru did manage to restore his soul, as Itachi suspected, then considering Sasuke's strength, even with the Mangekyou, a restored Orochimaru would have a good chance of seizing Sasuke's body.
"Oh well, Orochimaru recovering from his soul damage is just a feeling I have. It might not come true. Besides, by the time that happens, I'll already be dead. I've done everything I can to pave the way for Sasuke. If he still ends up dying, there's nothing I can do. I just hope you won't disappoint me, Sasuke. I'm not asking you to become renowned in the ninja world, just to keep yourself alive."
Itachi took steps toward Sasuke. Susanoo had been dealt with; now, with his last breaths, Itachi walked to Sasuke, who had regained control of his soul. Itachi's gentle smile, so familiar to Sasuke, appeared on his face. Sasuke was taken aback; Orochimaru's words about Itachi trying to let him live seemed true now.
Itachi knew that if Orochimaru's powerful Tsukuyomi had been used on him, he would have been killed instantly. The problem was, at that time, hatred had clouded his mind, and he saw everything as normal. However, when his body was taken over, he realized something was amiss. In the rush, Orochimaru had only suppressed Sasuke; he hadn't had time to utterly obliterate his soul and consciousness.
Thus, Sasuke quickly regained control of his body after Orochimaru left. At most, Sasuke's soul suffered minor damage during the brief period Orochimaru suppressed him. But for Sasuke, who had regained his body, he disregarded the slight damage caused by the direct collision of souls.
However, he had forgotten that Orochimaru could become so weak and vulnerable today, and that the accumulation of damage to his soul, even in small amounts, could be extremely dangerous. But for Sasuke, the current damage was negligible. After all, he had been marked by the Curse Seal of Heaven, and he didn't care about a bit more damage.
As long as he activated the Mangekyou Sharingan, his spiritual energy would increase again, and his soul would become stronger. Dealing with ordinary people wouldn't be a concern. With the Mangekyou, he could even see through most genjutsu, except for the illusions used by the likes of Uchiha Madara, Uchiha Izuna, Kabuto, Obito, and Tsunade.