In the original timeline, Itachi and Kisame would have retreated from Konoha after a brief skirmish with Kakashi and Guy. But in Aizen's world, the rules of engagement had shifted. There is no retreat from the desert of the God. As Itachi struggled to comprehend the "Cero" that had just cracked the ribs of his Susano'o, the space behind Naruto tore open like parchment.
Sasuke Uchiha stepped out, draped in the white robes of an Espada.
The Brother's Reunion: Void vs. Flame
Sasuke's face, once a mask of burning rage, was now terrifyingly calm—the stillness of a grave before a hurricane. He looked at Itachi not with hatred, but with a cold, divine superiority.
"Itachi," Sasuke said, his voice resonant and hollow. "You came seeking a 'weapon' for your organization to collect. Instead, you have found your masters."
Itachi's eyes widened, the Mangekyo spinning frantically. "Sasuke... those eyes. That energy. What has he done to you?"
"Pain was a long road, brother," Sasuke replied, stepping onto the white sand. "But Aizen-sama showed me that pain is merely an illusion for the weak who cannot grasp the Void."
Kisame, seeking to reclaim his pride, lunged forward. "Enough talk! I'll rip that tongue out of your head, brat!" He swung Samehada with mountain-crushing force.
Sasuke didn't even draw his sword. He simply looked at the shark-man with his Void-Sharingan.
"Bakudo #61: Rikujokoro."
Six rods of golden light erupted from the thin air, piercing Kisame's body and pinning him to the fabric of reality. Kisame roared in agony, feeling his spiritual energy being crushed under a weight he couldn't resist.
The Clash of Mangekyo and Void
Sasuke turned back to Itachi. "Show me your 'Tsukuyomi.' Show me the world you built out of lies and shadows."
Itachi didn't hesitate. "Tsukuyomi!"
In an instant, Sasuke was pulled into Itachi's dark world. For what felt like thousands of hours, he was subjected to the slaughter of the Uchiha. But Sasuke stood in the center of the blood and crosses, and he smiled. Suddenly, the red sky of the Tsukuyomi began to crack like shattered glass.
"Your world is too small, Itachi," Sasuke said, walking toward his brother within the illusion. "Aizen-sama does not just control the senses; he controls existence itself. Kyoka Suigetsu taught me that truth is merely what the strong decide it to be."
The illusion exploded. Itachi staggered back into the physical world, coughing blood from his right eye. His ultimate genjutsu had been shattered by the mere "presence" of Sasuke's soul.
The Decree of the God
As Itachi faltered, Aizen Sosuke appeared silently behind his disciples. No one felt him arrive until he spoke.
"Enough, Sasuke. Naruto. Our guests have received the message."
Aizen looked at Itachi, and that single gaze made Itachi's heart skip a beat. "Itachi Uchiha. You live to protect Konoha from the shadows, hoping to wash your clan's name in blood. But the Konoha you know no longer exists. It has become a mere backyard for my palace."
Aizen withdrew his hand from his robe. "Go back to 'Pain.' Tell him the Akatsuki are not collecting Tailed Beasts; they are collecting kindling for my fire. If he wishes to reclaim his 'weapon'..." Aizen gestured to Naruto, "...let him come to Las Noches himself."
With a wave of his hand, a massive Garganta (Void Gate) opened, swallowing Itachi and Kisame and spitting them out far beyond the borders of Hueco Mundo.
The Return to the Timeline: The Search for Tsunade
While Aizen solidified his throne, Konoha was in despair. Jiraiya, searching for Naruto, found no trace of him. The village elders decided to send Jiraiya to find Tsunade Senju to become the Fifth Hokage, hoping her medical expertise could heal the spiritual wounds Aizen left behind.
But Jiraiya was unaware that Aizen had already dispatched Sakura Haruno—the Third Espada—after him. Not to stop him, but to plant the seed of the Void within Tsunade's heart before she ever reached the throne.