After the lunch break, at precisely two o'clock in the afternoon, Kurotsuki Renya followed Bogen Akita, a senior instructor of the Kidō Corps, down into the reinforced basement beneath the Visored training facility.
The faint hum of reishi conduits lined the chamber walls. Bogen stood before Renya, his towering frame and composed expression exuding quiet authority.
"Renya," Bogen began calmly, "which Kidō have you mastered up to now?"
Renya replied respectfully, "I've already learned all the Hadō and Bakudō up to the intermediate level. For the advanced ones, I can perform a few — mostly through assisted incantation. I can only invoke the higher forms with partial chanting."
Though Renya had begun exploring elemental variants after his near-fatal encounter with a rogue Hollow, he had only managed to stabilize a few advanced-level Kidō.
Bogen nodded. "Advanced Hadō and Bakudō aren't just about reiryoku strength. Their structure is more complex. Only a few among the Gotei 13 can consistently perform them. Outside of the Kidō Corps, only a handful — like Captain Ukitake, Yoruichi Shihōin, Captain Kyōraku, Aizen Sōsuke, and Kisuke Urahara — could handle them properly."
Renya nodded, recalling those legends.
Bogen continued, "Even among the Vice-Captains, it's rare. Kira Izuru or Hisagi Shūhei could manage advanced Bakudō with chants. But among younger Shinigami, only Rukia Kuchiki and Kusajishi Yachiru ever displayed such control — and Rukia's spiritual pressure already bordered on Captain-class during the Thousand-Year Blood War."
Indeed, Rukia had eventually become Captain of Squad 13 — proof of her steady growth.
Bogen adjusted his cloak. "Typically, one requires at least Level 6 Reiatsu — Vice-Captain class — to safely perform advanced Bakudō. To abandon the chant requires Captain-class spiritual pressure, Level 7 or higher."
Renya's Reiatsu had finally reached that level. He could now manage unchanted advanced Kidō — though only two of them.
"So," Bogen continued, "how have you been handling the incantation-abandonment process?"
Renya hesitated. "Through rhythm and mental projection. I align the spiritual flow through the sigil pathways and visualize the end result instead of reciting the full verse. I was partly self-taught, but my Kidō mentor helped refine the focus."
Bogen looked impressed. "Not bad. That's the foundation of chantless casting. But remember — the more complex the spell, the greater the risk. If your reishi modulation is off by even a fraction, it'll fail… or worse, backfire."
Renya nodded. "That makes sense. Right now, I can only use two high-level Hadō without chanting — Hadō #73: Sōren Sōkatsui and Hadō #88: Hiryū Gekizoku Shinten Raihō. The first because it's lower-tier among advanced forms; the second because I've synced it with my Zanpakutō's nature. As for Hadō #90: Kurohitsugi, I can only form about one-fourth of its full power chantless."
Bogen frowned slightly. "One-fourth isn't enough. You should be able to reach at least one-third power unchanted. For advanced Bakudō, fifty to sixty percent of the chanted version is achievable. If you can reach that, it becomes viable as a main combat technique."
Renya's eyes widened. "That much? Even Aizen's chantless Kurohitsugi was said to be only one-third of full power."
Bogen smiled faintly. "And that's precisely why he was feared. Kurohitsugi borders on forbidden Kidō — the last of the high Hadō before the Kinjutsu level. The fact that Aizen could shape it chantless at all is monstrous. Even I can't match that."
Renya couldn't help but smile. "Still, one-third power could seriously injure a Captain. Which should we start with, Senior?"
Bogen shook his head. "Not Hadō. We'll focus on Bakudō — the art of binding. Especially the ones you already perform chantless."
"Bakudō?" Renya echoed curiously.
"Yes," Bogen said. "Bakudō is more adaptable in real combat. Even Vice-Captains can master advanced ones. The incantation-free versions, once stabilized, are faster, stronger, and perfect for your fighting style. Your Rikujōkōrō, Hyapporankan, and Sajō Sabaku are only operating at one-third efficiency right now — far too weak."
Renya listened intently as Bogen went on.
"You rely heavily on high-speed combat, Hollowfication bursts, Shunko, and Kidō fusion. Bakudō will complement that. The ability to restrain your opponent while releasing your lightning-based Zanpakutō attacks will multiply your effectiveness."
Renya nodded in agreement. "That does sound ideal. Pin them down and strike with Raijin no Ikari or Hiryū Gekizoku Shinten Raihō in one motion."
Bogen chuckled. "Exactly. Besides… I'm better at Bakudō than Hadō."
Renya grinned. "So honest."
It was true — Bogen's expertise lay in spatial and sealing Kidō. His unique techniques, such as Hachi Byō Shō, a layered barrier that induced subconscious avoidance, and Rokuhō Jōheki, a six-sided spatial lock that trapped targets within compressed dimensions, were master-level creations. Even most Captains would struggle to break them.
"Alright," Bogen said at last. "Let's start simple. Show me your Bakudō #61: Rikujōkōrō. Use it on me."
Renya extended his palm. "Bakudō #61 — Rikujōkōrō!"
Six beams of golden light shot forward and pinned Bogen's arms and torso in place. But within moments, the bindings shimmered and dissolved, evaporating harmlessly into the air.
Renya blinked. "It… melted?"
Bogen smiled. "It wasn't broken. I nullified it. By releasing a Bakudō of identical nature and energy pattern, you can cancel out an incoming Kidō. That's an advanced Kidō offsetting technique."
Renya's eyes lit up. "That's incredible. It's like Kidō-versus-Kidō combat."
"Precisely," Bogen said, folding his arms. "It's similar to how Yoruichi neutralized Suì-Fēng's Shunkō by matching its reiryoku output. The same principle applies here."
Renya's mind raced. If he could master that, he could counter enemy Kidō and Shunko alike.
"As eager as you are," Bogen warned, "that technique takes years of refinement. For now, let's fix your flow control. Your Rikujōkōrō channels reishi unevenly through the middle two pillars. I'll teach you how to stabilize that."
He began explaining — slowly, meticulously — how to align the spiritual current through Renya's hands and into the focal sigils, describing every subtle movement of energy modulation. Renya listened, absorbing every word, his focus unwavering.
A Kidō Corps instructor of Bogen's caliber was a once-in-a-lifetime teacher. Renya wasn't going to waste it.