"You've all grasped the theory behind Flash Blink. All you need now is relentless practice. Next, I'll teach you how to use Blut."
Hearing this, a look of absolute shock appeared on Saitō's face.
She stared at Kazuma in disbelief. "You're going to teach us Blut? An innate Quincy technique?"
Kazuma sighed helplessly. "I've already taught you Flash Blink, which incorporates Hirenkyaku. Why wouldn't I teach you something as straightforward as Blut? But remember my warning: absolutely none of this can be taught to outsiders."
Among the three, only Kōga looked entirely bewildered. "Master, what exactly is Blut? Why are Mistress and Captain Saitō so surprised?"
Kazuma couldn't be bothered to explain the history lesson again, so he waved a hand at the Sixth Division founder.
"Saitō, why don't you explain it to the kid?"
Saitō pouted, crossing her arms as she turned to Kōga. "You know about the Quincy, right?"
Kōga nodded quickly, eager to show his knowledge. "Of course. I've read the archival reports. They are the mortal enemies of the Shinigami. Master also just mentioned that Flash Blink incorporates their Hirenkyaku footwork."
Saitō nodded grimly. "Almost all Quincy abilities are based on the external manipulation of ambient Reishi. But Blut is different. You could say that a Quincy who can master Blut is guaranteed to be a captain-level threat. It's a high-tier skill divided into two types: Blut Arterie and Blut Vene."
"In the bloody war a thousand years ago, the Sternritter devastated our ranks with this ability. Blut Arterie pumps Reishi directly into the blood vessels to massively enhance offensive power, while Blut Vene hardens the skin to boost defensive power to absurd levels. Now do you understand why Batsu'unsai and I are so shocked?"
After hearing the explanation, Kōga's face mirrored their astonishment. "This is a forbidden, high-level Quincy technique... and you know how to use it, Master?"
He looked at Kazuma in awe, his heart filled with a burning curiosity and deep admiration for his overpowered, lazy teacher.
Saitō, however, still looked highly skeptical.
She scratched her head and asked, "Kazuma, although you just taught us the theory of gathering external spirit particles for footwork, we still don't know how to forcefully inject them into our own bloodstreams to achieve Blut. If just knowing how to gather ambient Reishi was enough, wouldn't every Shinigami be able to master it easily? Blut would be a dime a dozen."
Hearing Saitō's entirely reasonable question, Kazuma rolled his eyes in dramatic exasperation.
"Just because you can't figure it out doesn't mean I can't! Otherwise, what right would I have to be the one teaching you? Saitō, are you an idiot?" He shot her a fierce glare.
Taking a deep breath, Kazuma's tone turned serious and calm. "The key to using Blut lies in the absolute, microscopic degree of control over spirit particles. With your current level of control, none of you meet the requirements to trigger it on your own yet. But through the shortcut I'm about to show you, you will eventually be able to master it."
Kazuma beckoned to Batsu'unsai, a teasing, mischievous grin spreading across his face.
"You, come over here."
Hearing this, Batsu'unsai's heart tightened.
Seeing that familiar, playful smirk, she immediately assumed he was up to no good again.
Standing to the side, Saitō sensed the sudden shift in the atmosphere and immediately went on high alert.
Her right hand dropped to the hilt of her Zanpakutō, ready to draw.
"What are you two trying to do?" Saitō glared warily at Kazuma and Batsu'unsai, grinding her teeth.
"If you're planning to show off your sickening affection and make me feel like a third wheel again, I will definitely cut you both down right here!" She tightened her grip on her hilt, looking entirely serious about teaching the shameless couple a lesson in public decency.
Seeing the murderous aura radiating from the founding Captain of the Sixth Division, Kōga immediately bolted, hiding behind a nearby training dummy.
Kazuma was genuinely frustrated.
His original intention was simply to use Batsu'unsai as a demonstration dummy to teach them Blut, but Saitō's single-woman paranoia had completely misinterpreted the situation!
"Saitō, what the hell are you doing?!" Kazuma yelled. "I called Batsu'unsai over for serious training! Who has the time to rub their relationship in the face of a single, rabid dog like you? Don't be so damn sensitive!"
Saitō refused to back down, fully convinced the two of them were plotting something awful.
"Hmph! You two bastards, do you know how many times you've casually flaunted your romance in front of me today alone?"
Kazuma sighed, looking helplessly at Kōga, who was cowering behind the wooden post.
"Why did you run so far away? Get your ass back here!"
"Huh? How did I get dragged into the crossfire?" Kōga whined, slowly shuffling back toward the group.
Seeing Saitō's fiercely defensive expression, Kazuma found it amusing but decided to drop the teasing.
He raised his hands in surrender. "Fine, fine. To prove my pure, unadulterated good character, Saitō, you come over here first. How can you not trust me? I'm a really good person!"
Although still highly suspicious, Saitō decided to give him a chance.
She walked cautiously toward him, not forgetting to issue a final threat.
"Alright, I'll trust you one more time. But if you dare trick me into some romantic nonsense, watch me cut you down with a single slash!"
Kazuma smiled helplessly at Saitō's tense face and gestured for her to sit cross-legged on the dirt. Saitō obediently sat down, her sharp eyes fixed intensely on Kazuma.
Kazuma stepped behind her and gently placed his palm flat against her upper back.
Saitō's body immediately stiffened, and she twitched, wanting to pull away.
"Don't move," Kazuma ordered, his voice dropping into a serious, commanding register. "I'm going to forcefully circulate my own Reishi through your blood vessels for one complete cycle. You need to clear your mind, feel the exact pressure, and memorize how this power flows."
As Kazuma's refined stellar Reishi coursed violently into Saitō's body, glowing, branch-like patterns erupted across her pale skin.
At first, the dense, vein-like patterns flared with a harsh crimson light—Blut Arterie—before seamlessly shifting into a cool, defensive azure blue—Blut Vene.
After ensuring she felt the full cycle, Kazuma withdrew his hand, and the glowing patterns on Saitō's skin instantly vanished.
"You memorized the exact path my spirit particles took just now, right? Your body remembers the sensation. Now, try to force your own Reishi to follow that exact path," Kazuma instructed.
Saitō looked at her own hands as if she had seen a ghost.
He hadn't messed with her at all.
"Alright... you really didn't trick me this time. I'll try to replicate it myself."
Closing her eyes, Saitō concentrated fiercely, trying to force her internal spiritual power to circulate through her veins in the exact, violent pattern Kazuma had just demonstrated.
Slowly, the branch-like patterns reappeared on her skin, though the azure color was much fainter and flickered unsteadily.
Still, it was a massive success.
After helping Saitō memorize the complex circulation path, Kazuma repeated the grueling, forceful process with Batsu'unsai and Kōga.
By the end of the hour, all three of them had gained a rudimentary, instinctual grasp of how to trigger Blut.
Just as Kazuma was explaining the finer points of maintaining the technique to Batsu'unsai and Kōga...
CLANG!
A crisp, violent sound, like solid steel striking a diamond, rang out across the training grounds.
Kazuma whipped his head around and his jaw dropped. Saitō had drawn her actual Zanpakutō and viciously slashed her own forearm with a live, sharpened blade.
Fortunately, her faint, flickering Blut Vene had successfully activated just in time, blocking the steel.
"What the hell?! You crazy woman, what are you doing?!" Kazuma roared, his eyes wide in absolute disbelief as he stared at the maniac.
"Huh?" Saitō blinked innocently, rubbing her uninjured arm.
"I was just testing Blut Vene's practical defensive power. I've only ever used my sword to cut Quincy who were using it before. Now that I've learned it myself, I wanted to see how it felt on the receiving end." She said it as if violently attacking oneself was the most normal thing in the world.
Kazuma's mouth twitched violently.
He rubbed his temples, letting out a long, exhausted sigh.
"You literally just learned the absolute basics of Blut Vene and you're not even remotely proficient with it yet. Weren't you the least bit afraid that you'd fail to activate it in time and just chop your own damn arm off?!"
"If you lost your arm, I'd have to go find a giant eagle to carry you around so you could cosplay as a one-armed bandit!"
His tone was teasing, but it was heavily laced with genuine shock at Saitō's psychotic, impulsive experiment.
Saitō blinked again, seemingly entirely unaware of the lethal seriousness of her actions.
She offered a wide, foolish grin. "A one-armed bandit with a giant eagle? Hey, that actually sounds like a pretty cool title!"
Her absolute lack of self-preservation left Kazuma completely speechless.
Dealing with Saitō was always a wildly unpredictable, entirely exhausting experience!