Before a blackboard propped up by a few wooden stakes, two figures—one sitting, one standing—focused with absolute seriousness.
Aizen Sōsuke spoke with patient clarity, starting from the smallest details as he dissected the newly-developed kōdō spell patterns in depth.
"Judging purely by learning difficulty, binding arts are far more troublesome than destructive arts," he said calmly.
"Hadō only requires you to focus on destructive output—the whole point is to inflict maximum damage on the enemy."
"By contrast, bakudō must fulfill many different functions depending on the situation: restraining enemies, luring them, defending, escaping, disguising, confusing… the list goes on."
"Even though bakudō deals far less damage than hadō, in certain environments, combining multiple binding techniques can create results far beyond expectations."
"And naturally, the bakudō spell patterns are far more complex."
Kisaragi Akira listened with full concentration, occasionally nodding in agreement.He rarely attended the purely theoretical classes, but anything related to combat—sword, fist, spiritual flow, ghost arts—he took extremely seriously.
Thanks to that, not only could he absorb Aizen's explanations at high speed, he could also extrapolate, draw parallels, and even inspire Aizen in reverse.
A few of Akira's wild, out-of-the-box ideas had already shown Aizen more than one path he had never imagined.
"Based on your unique spiritual-body structure," Aizen continued, "and the combat patterns you've been developing—"
Before he could finish, Akira raised a hand to interrupt.
"I've got an idea," he said.
"Speak."
"The success of the Thunderfire Sword proves that fusing spiritual arts is possible. I think we should be able to merge different ghost arts, analyze the combined spell patterns, and then engrave them directly onto the spiritual body."
Akira spoke confidently, and Aizen listened intently—until Akira suddenly swerved:
"By the way, Sōsuke—want to learn the Thunderfire Sword?"
"No."
Aizen rejected it so decisively it was almost immediate.
He was already worried that spending too much time around Akira was corrupting his thought patterns.If he learned any more of Akira's bizarre techniques, he feared he might lose control altogether.
"Your idea is good," Aizen admitted. "But carrying it out will take time and effort. Ghost-art fusion isn't something achieved by talking."
"However… from what I know, Takegasa-sensei has already started experimenting thanks to your inspiration."
"You might be able to sit back and reap the benefits."
Akira frowned thoughtfully.
It wasn't that he doubted Takegasa Tetsusai's abilities—the man was the Grand Ghost-Art Instructor, and a shinigami with real skill.Technically speaking, the Ghost Arts Division was on equal rank with the Thirteen Guardian Squads, even if their combat power was worlds apart.But that very ranking proved just how impressive a Grand Instructor truly was.
Unfortunately… compared to Aizen Sōsuke, even Takegasa still had a "tiny, tiny" gap.Waiting for him to complete the research felt too slow.Working together with Aizen might accelerate things significantly.
Aizen brought the lesson back on track.
"Moving on—the spell pattern for Azure Fire Drop has subtle branch-lines on the third, sixth, and twelfth sequences."
He traced a pattern in the air—an imprint strikingly similar to the Red Fire Cannon spell.Heat shimmered instantly, spreading through the clearing.
Akira recorded everything with utmost seriousness.To avoid repeating previous mistakes, he copied the pattern several times until it sank into his instincts, and only then began engraving the new pattern into his spiritual body.
Food must be eaten one bite at a time; muscle grows one pound at a time.
And when it came to Aizen's guidance, Akira chose to trust him completely.
Hadō No. 33 — Azure Fire Drop. Begin engraving!
Akira's eyes widened. A streak of azure flame flashed across his gaze, then consumed both pupils in an instant.
Boiling-hot spiritual pressure surged through his body, engulfing his limbs and bones as if molten fire hammered him without pause.
At that moment, Kisaragi Akira was like a bar of raw iron—while the power within the spell pattern became a heavy hammer, pounding him with violent force.
Agonizing heat seared across every inch of his body.Even a passing breeze felt like it tore his nerves apart.
He had only advanced by two ranks, and yet the pain multiplied severalfold.
Thankfully, Akira's willpower was ironclad.Warm memories from his past surfaced in his mind, helping him bite down and endure.
As the engraving progressed, azure flames roared, wrapping around him and radiating intense heat into the air.
Aizen stared without blinking.Then—he noticed something wrong.
Within the burning azure flames, faint black marks appeared, crawling slowly across Akira's skin in twisting patterns.An eerie aura filled the atmosphere.
"What is that…?"
Aizen's eyes widened, attempting to analyze the nature of the black lines.
But the moment the final spell pattern completed, the black markings sank beneath Akira's skin and vanished completely—as though they had never existed.
Akira's eyes snapped open. Azure flames flickered for a moment before retreating, and the blazing aura instantly extinguished.
On his left ring finger, a new, pristine sigil remained.
"Nice. Strong. Powerful!" Akira exclaimed.
He stretched his limbs, running through the full "Era Calls for Strength" routine he used to gauge improvements in his spiritual body.
Every time he engraved a new pattern, his physical form strengthened—even if only slightly.
Not just that—his spiritual pressure had risen from Level 59 to Level 60.
Little gains added up into terrifying results.
Perhaps…One day he really would be able to explode a Menos Grande's head with a single punch, without using a drop of spiritual pressure.
The thought filled him with anticipation.
Just then, Aizen quietly explained what he had just witnessed.
"I see two possibilities," he said."First, the black markings might be residual power from the entity you've been offering long-term rituals to—part of Mimihagi's strength."
Akira nodded. That was very likely.
Aizen glanced at him, ignored the reaction, and continued:
"The second possibility… is that the markings came from your zanpakutō."
Akira froze, eyes widening.
"Whichever it is," Aizen said, "based on the current results, it appears harmless—and possibly beneficial."
He sighed lightly, giving Akira a complicated look as the latter hugged his zanpakutō with sparkling eyes.
He had thought his secrets were complicated enough.But compared to this guy?
Not even on the same level.
A unique spiritual body.A divine ritual.Innate talent.A mysterious zanpakutō…
"So what you're saying is…" Akira grinned as he held his sword, "I'm close to learning my zanpakutō's real name, unlocking Shikai, mastering Bankai, and stepping onto the peak of life?"
"I finally beat you at something, Sōsuke."
Aizen replied quietly:
"I already have Shikai."
Before the sentence even finished, Akira's expression froze—turning stone-stiff on the spot.