Itachi Rebirth: A Shinigami Tale

From a pile of rubble, Itachi emerged as he lifted a large chunk of debris off of him. Next to him, he could see Captain Unohana healing Urahara and Yoruichi.

"So you've been under there all along?" Unohana commented upon seeing Itachi. "After getting the Gotei 13 out of harm's way, I came to see if any of you were alive after that attack. I couldn't sense your spiritual pressure at all, Lieutenant Uchiha."

"My apologies Captain Unohana. I had no choice but to fully hide my spiritual pressure from Aizen while he was under my illusion." Itachi replied. Over forty years ago, while Itachi was still a student at the Shino Academy, he had placed Aizen under a genjutsu that he would be able to activate at any time one day. The Hogyoku prevented Aizen from falling under any of his genjutsu, but with Aizen being put under it before he merged with the Hogyoku and him not being aware of it, Aizen was fooled into thinking he had killed Itachi.

"Where are the two Kurosakis?" Itachi asked, not sensing their spiritual pressure anywhere.

"They left. I don't know the specifics but it appears Isshin had a plan for something with Ichigo inside of the dangai." Unohana responded. "Do you plan on going after Aizen yourself?"

"At this point, I don't have a choice." Itachi replied. 'Aizen has become too powerful for me to deal with. I can still damage him with the Totsuka Blade but his power has reached the point where if he is not severely weakened, I cannot seal him...I may have to resort to that…'

"Then allow me to heal you. These two are no longer in any life threatening danger so I can restore your reiatsu."

Itachi nodded and sat down in front of Unohana as she restored his reiatsu. Within a few hours, Itachi's reiatsu was fully replenished and stronger than ever. A spirit's power is increased when the shinigami is pushed to their limit in a dire situation. In his fights against Kaulico and Aizen, Itachi was pushed to that limit without ample time to recover. With his reiatsu replenished properly now, Itachi felt his strength increase.

"Thank you, Captain Unohana." Itachi said as he got up and opened a Senkaimon.

----

"Gin, the Hogyoku you stole. It does not matter whether it is inside of me or not. For it is rightfully mine." Aizen commented as he walked towards Gin, the hole in his c.h.e.s.t regenerating rapidly.

"Poison of that level, will not kill me. My reiatsu is far too great." Aizen raised his sword up into the air, ready to slash down on Gin. As Aizen's blade was about to sink into Gin's body, Gin suddenly vanished from in front of him.

"Uchiha!" Aizen said, shocked. "How are you still alive?!"

Itachi ignored Aizen's question and focused his attention on Gin.

"Uchiha, you're-"

"I watched the whole thing. Joining Aizen for as long as you did with the intent to only kill him, is truly commendable." Itachi said as he put Gin down.

"I'm curious as to how you evaded death, Uchiha." Aizen said as he slowly walked towards them. "Your eyes do not work on me."

"That is correct. My eyes do not work on the current "you." However, the "you" that was from over forty years ago when we first met at the academy, my eyes could work on."

"I knew you were always suspicious of me, but I hadn't anticipated you would have planned that far ahead. It appears I have underestimated you. However, this will not change the fact that you do not possess the power to defeat me as I am now."

"Even the strongest of opponents have a weakness, Aizen. Your own hubris will be your undoing." Itachi replied as his eyes glowed red and his Mangekyou Sharingan activated.

"You will regret facing me once again, you should have used the opportunity to escape!" Aizen said.

Before Aizen took another step forward, he stopped as a figure landed on the ground in front of him with great force.

"Kurosaki?" Itachi looked at Ichigo who was standing in front of him. He was in his bankai but his attire was slightly different. He now wore a black gauntlet and the chain of his blade wrapped all the way up his arm. He was also taller and his hair was longer than his original short spiky hair, now covering half of his face. With his sharingan, Itachi could still see Ichigo's reiatsu but couldn't sense it.

Mounted over his shoulder, was the unconscious body of Isshin. Ichigo quickly placed Isshin somewhere safe before returning back in front of Aizen in an instant.

"Itachi." Ichigo said without turning around and still facing Aizen. "We're going to stop Aizen."

"I'm disappointed, Kurosaki Ichigo. I no longer sense any reiatsu from you at all. Unlike me, you have failed to evolve." Aizen commented on Ichigo's new appearance.

"Aizen. Let's move. I don't want to fight here." Ichigo said calmly.

"Such a meaningless proposal. That is only meant for those who-" Aizen's words were cut short as Ichigo appeared in front of him, grabbing his face firmly as he carried him outside of Karakura Town into a mountain range and launching him into the ground.

Aizen put a hand on his face in shock at what had just happened as Ichigo stood in front of him and Itachi arrived shortly after.

"Uchiha Itachi, as I've said before, the way you are now, you are currently no match for me. Why bother even coming here." Aizen scoffed as he regained his composure.

"Fine...I'll show you something special." Itachi replied. The pinwheel patterns in his Mangekyou Sharingan began to rotate quickly as his reiatsu flared up. His body rose high into the air and became covered in an ethereal large armored head with a tengu nose and grew a large body clad in robes and ornate armor. Out of his back were a pair of giant orange wings.

Aizen looked up at the giant behemoth figure towering above him and laughed.

"It's large but it's no different than Komamura's bankai! I'm quite disappointed and confused as to why you would not use a technique such as this for so long."

"You'll find out soon enough." Itachi replied as he drew the Totsuka blade out with both hands. Aizen flew up and charged forward at Itachi as Itachi swung his sword horizontally.

Aizen blocks the slash with his own zanpakuto, but the force of the slash sends him flying into a nearby mountain. As Itachi finished the slash, the tops of the other nearby mountains flew into the air as they were cut off.

Aizen emerged from the rubble of the mountain he crashed into. He wiped a trickle of blood coming from his lip and grinned.

"I see. With destructive force of that kind, you fear your comrades may be struck as well. A foolish way of thinking. Uchiha Itachi, you also possess great power and potential. If you had joined me with Gin and Kaname-"

Aizen's words were cut short as Ichigo appeared in front of him. With no time to react to Ichigo's speed, Ichigo slashed across Aizen's c.h.e.s.t.

"That's enough from you, Aizen. You've been too talkative lately." Ichigo commented.

"Kurosaki…" Aizen teleported to a nearby cliff and glared at Ichigo. "You...abandoned your spiritual pressure for physical power is that it? I will admit for that brief moment, your physical prowess surpassed my own. But physical power will not be enough to protect you from this!"

Aizen raised his hand in the air and began reciting the incantation for hado 90.

"Kurosaki." Itachi called as he landed his Susanoo next to Ichigo. "Formation B."

"Right." Ichigo replied as he vanished from view.

"Fire Style: Fireball Jutsu!" Itachi quickly casted the hand signs as his susanoo shot multiple enormous fireballs at Aizen. Aizen stopped his incantation as several fireballs the size of small meteors flew towards him. Aizen teleported away as the fireballs vaporized the cliff he was just standing on.

"Getsuga Tensho!" Ichigo yelled from behind Aizen. Aizen turned around too late as a large wave of black reiatsu dug into his back and pushed him into another mountain, destroying the mountain in the process.

From the debris of the mountain, Aizen's reiatsu burst and flared up even further. Itachi and Ichigo watched as Aizen walked out of the dust cloud. His face was now completely black and the tips of his wings grew mouths. He no longer had the appearance of a human but instead, a monster.

"You may have bested me, but my power will continue to grow!" Aizen gloated. From one of the mouths on his wings, he fired a condensed fiery ball of reiatsu at Ichigo and Itachi. Itachi quickly summoned the Yata Mirror on his Susanoo and deflected the blast away from them. In the distance, what appeared to be a giant mushroom shaped explosion incinerated the landscape.

"Kurosaki. We can't afford to let Aizen keep growing at this rate. I have a plan for removing the Hogyoku from him, but you'll need to hit him with your strongest attack. If something happens to me, do not worry and continue fighting. It's part of the plan." Itachi said.

Aizen quickly charged in at the two of them. Ichigo charged towards Aizen, clashing swords with him briefly as Ichigo vanished while Itachi swung down with his Susanoo's blade, creating a large ravine in the earth. Aizen emerged from the dust of the impact and flew up the Susanoo's arm before Itachi had time to pull back. As he was about to make contact with the head of the Susanoo, Ichigo appeared behind Aizen, cutting him in the back. However, Aizen's wound healed instantly as he knocked Ichigo back with a kick before reaching his arm through the Susanoo's head, grabbing Itachi out of his Susanoo and causing the Susanoo to disperse.

As Aizen grabbed Itachi by the neck, he and Aizen locked eyes one more time as an evil grin formed on Aizen's inhuman face.

"Your eyes are useless against me!" Aizen yelled as he slashed Itachi in half from the head down.