"It's been a while… Allen."
With a distinctive and deep tone, a hypnotic and charismatic voice, a demeanor that was both elegant and sinister, and an unparalleled presence. The man who, no matter how many years pass, is always in the running for the title of best villain: Aizen Sosuke.
Just a moment ago, he was merely an unexpectedly pleasant academic, but now, in this very moment, he was the chilling Aizen.
"Aizen Sosuke..."
With just those few words, just that mere introduction, Allen understood why this world had changed. The death of Yhwach, Ichigo's non-existence, Kempachi's disappearance, and Urahara turning evil.
Allen wanted to blame Aizen for everything, but he knew it was his own fault. He had never considered the consequences of his streams on his viewers.
It's absurd that a mere broadcast, made with the intent to entertain, to amuse, could destroy a world. But every person who watches, even now, the people in the chat, acquires knowledge they shouldn't possess. For most people, this information would be harmless, but for someone like him...
Allen smiled, feeling his organs burn.
"It's been a while? That's what you say after ruining this world?!"
"Allen Walker... who are you saying that to, me or yourself?"
Aizen's response was harsh and indifferent, something easy to understand. One thing is to witness chaos, war, and death in any world, but when the origin is oneself, the meaning changes.
This world is not an altered reality; it is a version of the world faithful to the canon. However, because of the knowledge Aizen gained from watching all his old videos, including those where he discussed things from Bleach, in those conversations, there was a pile of knowledge that should never have fallen into the hands of someone like Aizen.
"Do you regret it, Allen Walker?..."
"Aizen!"
There was no kindness or a shred of doubt, from either side. Unlike previous encounters with enemies, Aizen was aware of nearly all his powers already used, and Allen himself still had a great understanding of Aizen Sosuke.
"Domain Expansion: Infinite Void."
"Bankai"
They both attacked at the same time.
'Ban...kai?!'
Allen didn't allow himself the luxury of distraction, and he couldn't let him use his Bankai. Allen forced his cursed technique to activate, while simultaneously extending the domain of the Infinite Void. Both processes caused his brain to burn, so he had to use his cursed technique.
'Limit of Fate.'
Time slowed before his eyes, and the damage to his brain decreased. Allen could process information as fast as light.
He didn't let his surprise distract him. Using the Limit of Fate, Allen increased his control over the Infinite Void. Thanks to his actions, his domain expanded faster than Aizen's bankai.
'Allen...'
Aizen opened his eyes when he noticed this, but it was too late to respond; the changes occurred in nanoseconds.
Aizen was overwhelmed by the infinite information flooding his mind. This was enough to interrupt the activation of his Bankai, but not to stop him. Without wasting time, he moved his sword, splitting the domain in half.
"As expected!... he's capable of resisting and processing the massive information for a few moments before being overwhelmed!"
"Are you surprised?" Aizen asked with a serene look, even after experiencing the Infinite Void.
Aizen moved against Allen at a speed impossible to follow for him in his current restricted state.
"Damn," Allen activated his Infinity, barely blocking a cut that almost split him in half. However, Allen noticed something—part of his clothing had torn, even though he was protected by his neutral Infinity.
Gwen – Didn't he break the domain too easily?!
Felicia – Not just the domain, the Infinity doesn't seem reliable!
[Error: There is a serious alteration of the structure of this world... Host, according to readings compared to other captains, the man before you has approximately 112 times more reiatsu than them... and it's still growing!!]
"...!"
Without time to react to the system's words, Aizen appeared above Allen, his sword already in hand. The pressure he released was overwhelming. The system took care of containing it, or people could die simply by Aizen's presence.
"Allen... I've wanted to meet you for a long time... I've wanted to thank you for letting me see the world from so many perspectives... for making me realize I don't have to suffer in this world..."
Allen saw Aizen's sword descending toward him. 'If that strikes the human world, the whole city will be split in half!'
'System!!'
The world changed, and Allen was teleported to another dimension with Aizen. It was a world that mirrored the human world but without people.
[It's from the other side of the mirror.]
It is said there is a dimension on the other side of the mirror, a strange place where everything is reversed, but at the same time, a reflection of the world, with no people, only structures.
Allen stopped worrying about the damage and summoned his dark, scarlet sword to take the blow.
Allen was naive...
With the first strike, Allen's knee buckled, and he fell to the ground.
"Huh?"
"Allen... don't underestimate me..." Aizen said; that would be his first and last courtesy warning to Allen.
'Underestimate you?!' Allen grunted, tasting metal in his mouth. 'With just one strike, my strength was bent, with just one strike my bones almost shattered, my organs were damaged, regardless of my spiritual energy, I still have my massive cursed energy and Chi protecting and reinforcing my body, which should even surpass Sukuna and Gojo-sensei together... with much less, I faced Doomsday and Hulk Worldbreaker!'
Allen couldn't even gasp when the next attack came, this time diagonally from below.
The sword strike pushed Allen, who couldn't hold on and was sent flying.
...
Suspended in the sky above the sea, he lost consciousness for a moment... his current power wasn't enough to face Aizen.
"Then I'll break that limit, Domain Expansion: Breaking–"
"I won't let you..."
Aizen appeared and grabbed Allen by the face before flying with him. His speed was enough to cross the world in an instant. Aizen dragged Allen across the ground, through the Asian continent.
"Aizen!" Allen growled.
"...?" Aizen opened his eyes when he saw several purple orbs around him, about to strike. He smiled and released Allen, slamming him into a volcano. Allen entered the searing magma, clinging to his consciousness.
Allen was fighting with restrictions against a monster whose power exceeded the level of his world.
'How?... How did he obtain that power... even if he returned to the past, this makes no sense...'
[Host, this is dangerous, it's better to release the restrictions and face the consequences.]
'I'm fine...' Allen got up and sharpened his gaze as his eyes turned red, and his dark zanpakuto appeared. 'I'm still not at my limit...'
...
Aizen appeared in an instant, both were in the middle of the magma but could see each other. Aizen attacked with his sword. However, something strange happened—Allen seemed to lose the previous tension as his hair turned black.
Aizen narrowed his eyes in confusion. Allen's demonic power was one of his weaker powers; he shouldn't use it in this situation.
Aizen had his doubts but didn't stop and attacked Allen. Allen's hand extended, stopped, and blocked the sword as if it were nothing.
"Allen, did you release the restrictions?"
It was logical for Allen to do so; otherwise, he would be killed by Aizen.
"Restrictions? What the hell are you saying?... and more importantly who are you?"
Aizen felt a chill run down his spine. He couldn't move his zanpakuto at all. Moreover, Allen's aura had changed.
When he lifted his gaze, there was an expression of confusion and disgust.
"Allen?..." Aizen's eyes shrank, "No... You're Void!"
Void smiled, and an instant later, Aizen was cut into pieces... he still had an incredulous look on his face as his body parts fell off. But Aizen immediately regenerated, even without the Hogyoku, Aizen was still immortal.
"I see... so that's it, you obtained a very interesting power, Allen..."
However, Void buried his fist in Aizen's stomach, not letting him speak. "I don't like to spend more than one strike on my enemies other than Allen; it makes me look weak..."
"Ahhh!"
Void's strength shattered the volcano into pieces, and the lava was thrown in all directions, also creating massive tsunamis. Fortunately, no one was alive in this dimension.
Aizen regained consciousness in space. "My soul was nearly torn apart by that thing... I didn't see that fight live, but I did see the video; even now, he is weakened and has the power to kill me.... but how did it come to this world, and where is Allen?"
"Where are you looking?"
Aizen opened his eyes; a voice came from behind him. When he turned, he saw a man in a red cloak hitting him. The force was so great that it sent him flying through space.
"Another monster!..." said Aizen, stopping the impulse. Now stranded in the infinite void, he didn't return immediately. Instead, Aizen used the time to heal the damage from those two. "I understand what happened now..."
Satisfied with his deduction, Aizen squinted and teleported.
...
On the surface of the Earth, Allen tried to recover as his hand gripped his black/scarlet zanpakuto, and a black smoke emanated from his body.
"Just a moment, and I was left in this state?!"
Allen held his second zanpakuto.
"Release the Registry ******...."
Aizen appeared in front of Allen but did not attack. Instead, he looked at the sword with interest.
"Your two zanpakutos are quite interesting..."
"..." Allen did not respond to Aizen, as his arm was numb after using, the Shikai of his second zanpakuto.
"I see... judging by the word you use to activate your shikai, I assume that sword represents everything you've carried in your life. And even, in a non-metaphorical way, it allows you to manifest your former enemies... how terrifying. If I weren't limited by your meager Reiatsu, that Void memory or even that Superman might have killed me..."
Allen could not respond. His eyes were blurry, and his mind was on the verge of collapsing. Aizen was right about most of his speculations. This zanpakuto allowed Allen to manifest his former enemies, who, unlike him, were not limited by the world but by Allen's spiritual energy.
Unfortunately, he had underestimated the side effects he would have to suffer from. Just a moment of summoning Void's memory took him to a dangerous limit.
[Allen, I'll get you out of this world!]
'No!'
[Don't be stubborn. Even if it was only a weak version of both, Aizen withstood a blow from that Superman Prime that almost killed you, and he even resisted for a moment against Void!]
Allen understood. He didn't know for how long, but the Aizen before him had been preparing for his arrival for a long time.
Running away wasn't a bad bit but Allen didn't want that.
Infinite Void had canceled Aizen's Bankai by overloading his brain, but there was no guarantee it would work again. Allen placed his hands to activate Sukuna's domain.
Aizen smiled. "Bankai."
"I won't let you! Domain Extension: Infi—"
Allen tried to interrupt Aizen's Bankai again, but he didn't have the time.
Everything around him was erased, leaving only a frozen wasteland with distant mountains. The sky and the earth were no longer what they had been. If this were the real world, it would be like eradicating all life in an instant.
"What?"
Destruction?
Reality alteration?
A dream?
An illusion?
Hypnosis?
A lie?
A different world?
A different dimension?
"I don't know..."
Unable to comprehend the full magnitude of Aizen's current power, Allen watched in disbelief as the world on the other side of the mirror was devastated in an instant.
Allen could feel the intense cold around his throat, the freezing wind, dry trees, and a cloudy sky...
'SYSTEM!'
Allen wanted to ask his most faithful companion, but the system didn't respond.
"Allen, I think you've made a mistake..."
Aizen didn't let him think. His sword arrived in an instant. Allen summoned Divina Comedia to block Aizen's attack, but the impact sent him backward.
"Urgh!"
Allen felt pain in his head. His Reiatsu was too low, his cursed energy wasn't infinite, and his chi was reserved to protect and heal him. Also, in this dimension, he couldn't use the Auswalen. Allen refused to back down, he wanted to face Aizen to the end.
"Even now, you still hold that gaze..." Aizen's words were calm. His gaze lacked hatred, contempt, or mockery, but it also lacked sympathy, kindness, or closeness. It was the gaze of someone serene and respectful.
Aizen stood before Allen but seemed more like a spectator, watching with interest what was happening.
"Let me ask you a question..."
"You have an arrogant look for a defeated villain, Aizen."
"Allen, you fought hard to stop the activation of my Bankai, but what makes you think I ever stopped using it?"
"...!"
Allen gritted his teeth. He couldn't fall for Aizen's lies. He couldn't trust anything he said. Moreover, he still had many cards to play. It was true that Aizen's power wasn't something Allen hadn't faced before, but even this being another dimension was still the world of Bleach, was Allen willing to give up everything just to defeat Aizen?
'No...'
Allen mocked himself. Regardless of his desires, turning Aizen into this monster was his fault.
Allen put on a serious expression.
Aizen raised his guard. These were the eyes of a calm Allen, the eyes that had faced those terrifying monsters Aizen had just experienced.
Almost imperceptibly, Aizen smiled. 'Finally, you're taking me seriously...'
"Allen." Just before Allen released his restrictions, Artoria appeared, touching his shoulder. "You don't need to sacrifice yourself... we're with you..."
Allen smiled, causing Aizen to frown.
Artoria stepped forward and faced Aizen with her sword.
"You're not on my level to face me... Artoria Pendragon..."
Aizen's words meant nothing to her.
"Alright, show me what you can do..."
Aizen's eyes widened when he saw Allen behind Artoria raising his hands. No, it wasn't Allen; it was Void.
Void pointed at Aizen. "Disperse... Restriction..."
The black smoke left Allen's body, Void became an exhausted Allen, and Bocchi appeared to hold Allen.
Aizen felt his connection with his zanpakuto severed for a moment, which deactivated his Bankai, which he had barely used. Then, his power was restricted to a tenth of its original strength.
'What a monster...' Aizen smiled instead of getting angry.
Artoria unleashed all her power and struck Aizen. Even at a tenth of her power, she was at least a dozen times stronger than a captain.
However, Artoria wasn't weak. Her power exploded, and Aizen's feet sank into the ground. The force of the impact lifted huge rocks around him.
Aizen cut with his sword. It was a casual attack but created a massive slash that pushed Artoria back, forcing her to retreat.
Allen channeled chi around him to recover quickly while Aizen raised his fingers toward him.
"I won't let you!"
Esdeath appeared and froze Aizen in a giant glacier. Aizen broke the glacier and grabbed Esdeath by the neck, but immediately many chains momentarily stopped him. Esdeath freed herself from Aizen's hand and moved away.
"This is useless; we're not in the same league...dolls"
Makima ignored Aizen's words and mocked him. "Look up..."
"Bastard, how dare you hurt Allen-sama?!"
Albedo fell like a meteor, hitting Aizen with his giant axe.
"What troubled women you have, Allen."
...
Allen smiled seeing that the girls were already able to restrain Aizen, so he concentrated on his recovery. However, there was an uneasiness in his heart, and it was because of Aizen's words. Would it be true that he was always using his bankai... and if so, what did he do?!
===
A/N: Can you imagine the whole arc, no, the whole story to be Aizen's Bankai? hahaha... ha 🗿