The strongest resistance force in Hueco Mundo has surrendered, and the Arrancar Army controls 70% of the territory. The remaining 30% is barren land with sparse Reishi.
Menos Grande generally avoid those places, especially Adjuchas, who need to hunt. There's little prey there, and going there would slow down their evolution.
Zero handed over the management of the research institute to Szayelaporro, but of course he didn't have the final say alone. Several Scientific Hollows loyal to Zero were constantly monitoring him and sharing his power.
The research institute continues its research, and even without developing the Hōgyoku, they are gradually working on Arrancar Menos Grande.
Because they had captured several Quincy, and the powers of Hollows and Quincy were polar opposites, each a poison to the other, the Scientific Hollows injected Quincy power into Seigen's body, which saved his life.
Research into the powers of Quincy, Shinigami, and Hollows is ongoing; the half-Arrancar created here is simply a Hollow with Shinigami spiritual power placed inside it.
Some Scientific Hollows have begun researching how to integrate the three elements, attempting to find a way to push Adjuchas towards complete Arrancar.
Several years passed in the blink of an eye, and it was already 145 years before Aizen was sealed away.
The silent Hueco Mundo was forgotten by ordinary Soul Reaper, but the Captain-level clearly remembered the feeling of helplessness as they lay prostrate on the ground.
After that defection incident, the Captains of the Gotei 13 trained even harder, including the usually lazy Shunsui Kyōraku; they didn't want to be bullied anymore...
Meanwhile, Aizen, who was shrouded in darkness, remained quiet for a long time because Hirako, who had recently taken over power, was difficult to deal with, and he often assigned various tasks to Aizen, who was now the Vice-Captain.
In order to move around easily again, Aizen spent the past few years investigating Hirako's personality, habits, and social interactions, down to the smallest detail, such as how many hairs Hirako shed each day.
Once he understood Hirako's patterns, Aizen was about to take action again. Over the years, he had gained a loyal subordinate—the blind Kaname Tōsen...
"Sōsuke, you and Tōsen seem to get along quite well! You're always hanging out together!"
Hirako walked ahead of Aizen, casually probing Aizen. He had always felt that Aizen was a dangerous person because he handled all the team affairs so well that he himself hardly had to do anything.
"No, I just admire his ambition. In fact, Tōsen and Sajin Komamura from the First Division are best friends..."
Aizen a beat. He suddenly remembered that Tōsen had been by his side for five days this week, even when he met Hirako.
"Yes, I also think highly of this young man. The Ninth Division is short Fifth Seats, and I think Tōsen's strength is sufficient. I wrote a letter of recommendation for Kensei!"
Hirako was indeed impressed by Tōsen's efforts; a blind man like him could graduate with excellent grades, so he must have grown a lot after several years of training.
The reason for kicking him out this time was simply to prevent him from associating with the dangerous Aizen.
"Really? That's great! Tōsen can stand on his own now!"
Aizen an expression of genuine joy for his subordinates, revealing no flaw whatsoever... Hirako was indeed glancing sideways to observe Aizen's expression, but all he saw was his 'sincere' smile.
Of course we should laugh. Being in the same Squad makes things a bit inconvenient. Hirako didn't say anything, Aizen would kick Tōsen to another squad...
After inspecting the various tasks within the team, Hirako began to walk towards other teams, Aizen naturally followed. The two hardly had any further conversations outside of work.
The strange Vice-Captain remained silent, lost in thought. As they rounded a bend, they encountered the elated Shusuke Ihana.
"Hirako, Vice-Captain Aizen, it's been a long time!" Ika greeted her happily, a smile on her face.
"Vice-Captain Ika." Aizen nodded slightly in return.
"Ah! It's Ika! It's been so long! Where are you headed?"
Hirako snapped out of his reverie, flashing his signature eerie smile. He had a good relationship with his former boss and his sister, though he rarely saw Ika these days.
"Yeah, I'm going to Rukongai for a stroll. My favorite clothing store has new styles. See you later!"
"The Fourth Division's salaries are really high..."
"Hehe, we're mainly busy and don't have much time to spend money. See you later!"
Ika didn't exchange many Hirako, but left after a brief chat, leaving Hirako muttering to herself, "She's finally moved on from the loss of her brother! That's good."
"It must be because Captain Unohana made her the Vice-Captain of the Fourth Division! She forgot her sadness when she was busy with work."
Aizen suddenly uttered those words, and a glint of light flashed across his glasses.
Hirako slapped his forehead. "Oh yeah, Sōsuke, I almost forgot, she's become the Vice-Captain again..."
He then remembered that the Fourth Division Vice-Captain, Kiyōnosuke Yamada, had recently applied for a leave of absence and had temporarily surrendered his Zanpakuto. The Central 46 had agreed, Unohana had reinstated Ika, who was serving as Seated Officer in the Fourth Division, back as Vice-Captain.
Aizen didn't reply, a suspicion creeping into his mind: 'Perhaps there's another reason!'
Two months later, in the eighth district of North Rukongai, a relatively prosperous area, there are frequent attacks on spirits from the Outskirts, and the situation has been escalating recently, with the Soul Reaper frequently coming and going.
Seigen was drinking with a few henchmen he'd recruited from Rukongai when he saw a group of Soul Reaper running outside the tavern window. He immediately slammed his fist on the table and roared, "That bastard rules Hueco Mundo, and he doesn't even restrain his subordinates?"
The henchman stopped the Hei Bashi and boasted, "Boss, what's up?"
Seigen realized he had lost his temper. "It's nothing, let's keep drinking!"
'Speaking of which, Ika must be very busy lately! But it's good to be in the Fourth Division! No need to face danger...' Seigen thought to himself about his sister's situation.
He had been back from Hueco Mundo for a long time. He had contacted Ika several years ago, let her know he was safe, and then went into seclusion, barely making a living as a gang leader.
To avoid being recognized, Seigen dyed his hair black and usually wears a half-mask.
However, after that Ika would visit him every month during her time off, and sometimes she would try to Seigen to return to the Gotei 13, but Seigen refused.
Today, Ika came again, meeting Seigen in the courtyard full of children, and once again tried to persuade him to return to the Gotei 13; Seigen, on the other hand, advised his sister to get married, so that he could leave here in peace and wander around the Soul Society.
The siblings often disagree, and neither of them has absolute authority, which leads to another unpleasant breakup, but this is all normal.
But Ika didn't notice that she brought a tail with her this time...
After Ika had gone far away, Seigen's gentle gaze towards his family suddenly turned sharp. Then, he took a few Shunpo and walked to the Outskirts, where he stood still.
"How much longer do you want me to wait? It's time to come out!"
Seigen raised his hand, seemingly in Seigen, a figure appeared out of thin air in front of Seigen —it was the refined Aizen.
Aizen smiled and said, "Captain Shusuke, it's been a long time!"
Seigen narrowed his eyes, his killing intent palpable. "So that's how it is. It was you who made me Hollowfication Sōsuke Aizen!"
"Did Nangong Ling tell you? He must have guessed I would come looking for you! Otherwise, if you wanted to hide, you wouldn't have been in contact with Vice-Captain Ika so frequently, and I wouldn't have been able to find you."
Aizen had analyzed everything; he also realized that Seigen was just Bait, and a very obvious Bait... In terms of intelligence, Zero was clearly not as good as him.
'This guy, knowing it's a trap, still came? Does he think he's safe?'
Seigen Aizen was startled. He had only heard Zero analyze Seigen's abilities before returning: this guy was very likely the thief who invaded the Great Spirit Book Gallery. His Zanpakuto was of the Illusion type, and his strength was far greater than that of an ordinary Captain. Moreover, he had Hollowfication Seigen in order to seek the evolution of his power.
Zheng Yuan knew very well who was Seigen by "normally." When he didn't unleash his Zanpakuto, his Reiatsu was usually only 1.4 cha, slightly stronger than some powerful Vice-Captains. His Shikai was only 2.1 cha, and his Bankai was only 3.7, less than 4 cha.
"Aizen, what exactly is your purpose? Do you want to control the Seireitei?"
Seigen couldn't help but want to know the situation, and was also trying to buy himself some time.
"My purpose is simple: first, demonstrate the term 'Hollowfication' you just mentioned! The fact that you survived and even uttered it suggests you've mastered this power."
Aizen stated his current small goal: to see the Hollowfication. He needed data to see if his research findings were feasible.
Even if Seigen is unwilling to become Hollowfication on his own, he will force Seigen to Hollowfication later.
'Yes, when I agreed to be the Bait, Zero mentioned that this guy might be seeking a breakthrough to become stronger.'
Seigen was taken aback for a moment, then suddenly attacked. "Who knows what you're talking about! Hadō #63: Raikōhō, Raikōhō!"
Aizen's lips curled into a smile. He dodged with Shunpo and then slashed at Seigen's shoulder, causing him to stagger and almost fall. The difference between the two was purely a matter of strength.
"You dare to fight me with this level of strength? You should just Hollowfication! Your sister is returning to Seireitei; you wouldn't want anything to happen to her, would you?"
"If you dare do anything to Ika, you bastard, I will definitely kill you!"
Aizen, sensing the opportune moment, subtly provoked Seigen with words. Sure enough, his only remaining close relative became his Achilles' heel.
Seigen placed his right hand on his forehead and pulled it down, revealing a pure white mask with only eyes visible. Seigen's Reiatsu immediately surged.
The increase is significant, jumping from 1.4 vehicles to 2.6 vehicles, almost doubling. However, if this output power is maintained, the sustainability of the Seigen will inevitably be weak.
Aizen merely frowned; this was far worse than he had anticipated. It couldn't be considered an evolution at all; it was merely a suppression and control of Hollow power. Seigen's Hollowfication Experiment had failed.