"Is there really no way to break through it, to push every ability past its limits and strengthen them all?" Sōsuke Aizen asked as if he were lecturing in a classroom, guiding students toward the answer before providing it himself. "Of course there is. But only one way. The Hollowfication of a Shinigami."
Rukia Kuchiki thought of the skull mask worn by Muten Natsu. After Hollowfication, Muten Natsu's power had been terrifying.
"The Hollowfication of a Shinigami, and the Shinigamification of a Hollow. By removing the boundary between these two extreme existences, they can evolve toward a higher realm. In theory, this method has already been proven feasible." For a brief moment, the smile on Sōsuke Aizen's face disappeared. "And I have taken particular interest in Hollows becoming Shinigami. Several times I successfully released Hollows that were close to becoming Shinigami. Besides the type you just saw, there are also Hollows capable of concealing their Reiatsu, Hollows that probe the memories of souls and mimic them..."
A vein bulged on Ichigo Kurosaki's forehead.
"You bastard!!!"
Yasutora Sado grabbed both Ganju Shiba and Ichigo Kurosaki, restraining them with one hand each.
"However, it is still too early to call them a new species. Everyone except me interfered out of ignorance, and in the end they couldn't find even a single viable method." Sōsuke Aizen paused briefly. "But Kisuke Urahara created something. What he produced could erase the boundary between Hollows and Shinigami in an instant. It is a substance that surpasses the common sense of Soul Society. The Hōgyoku."
"It is an extremely dangerous substance. I imagine he must have realized that as well." Beneath Sōsuke Aizen's calm voice was a subtle tone that sounded both like admiration and contempt. "But the result was... even he, the one who created the Hōgyoku, could not find a way to destroy it. With no other option, he came up with a solution. Place a barrier around the Hōgyoku and hide it deep within another soul."
"The best way to hide something is to put it somewhere random. Somewhere even you yourself would not know." Sōsuke Aizen's gaze fell on Rukia Kuchiki. "For example... inside some random child in Rukongai."
"When Muten Natsu left Soul Society, he handed you a great opportunity. No one in Soul Society could threaten your safety." The corners of Sōsuke Aizen's mouth curved upward. "So I arranged for you to join the Thirteenth Division and be stationed in the city where Muten Natsu lives. Then I sent Hollows to hunt him, forcing Muten Natsu to act. After that, when this Quincy used Hollow bait, I released a Menos to draw Soul Society's attention to your movements."
Uryū Ishida trembled.
No wonder the number of Hollows back then had been so horrifying.
"This would force Rukia Kuchiki to return to Soul Society as a criminal. There are two ways to extract the Hōgyoku. The first is to use the destructive heat of the Sōkyoku to vaporize the soul that acts as its outer shell, allowing the Hōgyoku to be removed."
Sōsuke Aizen took a tubular device from his robe.
"The second method comes from Urahara's previous research, which I discovered in the Daireishokairō after killing Central 46. This is a device capable of extracting foreign objects from within a soul..."
Flowing black flames suddenly erupted.
Like a dark sky rising in an instant, the cold karmic fire condensed almost into solid form. Accompanied by violent blade pressure, it slashed toward Sōsuke Aizen.
The terrifying force of the attack, merely from its aftershock, sliced away half of the Sōkyoku Hill.
Yet the powerful strike was effortlessly blocked by Sōsuke Aizen's blade.
A piercing screech rang out and abruptly cut off.
"Do not be too surprised. Trying to capture an ant without crushing it is not easy." Sōsuke Aizen looked at Muten Natsu standing just inches away. "That is why you wait until the ant is ready and approaches on its own before acting."
Muten Natsu swung Bokukō, but an overwhelming Reiatsu descended, pressing down on him until he could not move.
"You have made three serious mistakes," Sōsuke Aizen said as he pushed aside Myōki.
"First, Hellfire can destroy the stable structure of Reishi, but if the Reiatsu is strong enough, even the flames of hell can be suppressed.
Second, after learning the ability of my Kyōka Suigetsu, you divided your strength to control the spread of spirit ink and used Hellfire to pinpoint my location. That split your power. But in truth, when facing you, I had no need to use Kyōka Suigetsu at all.
Third..."
Sōsuke Aizen slightly raised his eyes. The tubular device in his other hand twisted and deformed, wrapping around his palm and turning dark green, its surface densely covered with fine patterns.
Six sharp pillars suddenly burst from the surrounding ground.
The power they released froze Muten Natsu in midair.
"My target was never Rukia Kuchiki. You simply chose the wrong thing to protect."
Sōsuke Aizen's hand pierced straight through Muten Natsu's chest. When he withdrew it, he held a circular gem wrapped inside a transparent polyhedron, glowing with a blue black light.
"Look. The moment Rukia Kuchiki is involved, you rush in without hesitation and hand me exactly what I want."
Black flames churned violently inside the transparent polyhedron, the spherical gem rolling endlessly within.
Once it left Muten Natsu's body, fine cracks began to appear across the polyhedral barrier. Hellfire leaked out through those fractures.
A slight pressure from Sōsuke Aizen's fingertips released an overwhelming Reiatsu that completely suppressed the black flames, forcing them back inside.
Muten Natsu's body suddenly looked hollowed out. The flaming tail behind him scattered into the air, and the Hellfire burning across his body faded away.
"How surprising. So it was something this small."
Sōsuke Aizen held the gem between his fingers.
"This is... the Hōgyoku."
"Muten!"
Rukia Kuchiki gripped her Zanpakutō and rushed forward.
Before she could reach him, Sōsuke Aizen had already thrown the limp Muten Natsu toward her.
Rukia caught him, and Orihime Inoue immediately began healing him.
But the hole in Muten Natsu's chest had already closed on its own and vanished completely.
"The soul itself is perfectly intact?" Sōsuke Aizen put the Hōgyoku away. "What impressive craftsmanship."
Rukia Kuchiki stared at Sōsuke Aizen, fury blazing uncontrollably in her eyes.
"It seems you have already realized it." Sōsuke Aizen replied with a faint smile. "As long as you were judged a criminal, Muten Natsu would definitely return to save you. If you were sentenced to the Sōkyoku, he would stand in front of it to protect you. If you encountered danger, he would approach that danger himself."
"Every time Muten Natsu used Hellfire, the Hōgyoku was refined a little more perfectly. And in the end... it would be delivered into my hands."
"So from the very beginning..."
Rukia Kuchiki held Muten Natsu tightly, a deep fear rising from the bottom of her heart.
"Was all of this part of your plan?!"
"There were still a few deviations," Sōsuke Aizen said calmly. "I did not expect that the Hollow I released, the one with the ability to replace severed limbs with substitutes, would run into Muten Natsu and cause him to erupt with such tremendous power."
"Erasing the traces of that incident actually took me quite some time."