"Those who do not understand the true essence of sword forms believe that mana must be divided and used according to each posture."
As he gently stroked the wooden sword, Aizen spoke to Lucian.
"When striking powerfully, they focus it only in the arms. When blades meet, they focus solely on pressing down with weight. When evading, they concentrate exclusively on the legs. Each time, they make a great show of moving mana throughout the body."
"…Is that not correct?"
"Of course not."
The instant reply made Lucian shrink back slightly.
In his previous life, he had used sword forms in exactly that way, and hearing Aizen deny it so decisively was embarrassing.
"Then how should mana be used?"
"It should be used like this."
Whooong—
As Aizen swung the wooden sword through the air, a bluish aura flowed out from his body.
At the clearly visible shape of the mana, Lucian flinched.
Unbelievable… he manifested mana throughout his entire body without any prior buildup.
When renowned knights unleashed their power, mana usually appeared only briefly, and only around the specific part they had focused on.
Yet here Aizen was manifesting mana across his entire body, merely to use it as a teaching aid.
"Watch carefully."
Hoo—
Each time Aizen moved, the manifested mana writhed and shifted in form.
How mana flowed with each posture.
Where it needed to be concentrated when sudden changes occurred.
All of it was so vividly clear it felt almost within reach.
While Lucian stood spellbound by a technique bordering on the miraculous, the demonstration of the sword form was already drawing to a close.
"Do you understand?"
"P–Please show it to me once more."
"As many times as you like."
At Lucian's request, Aizen smiled and demonstrated the sword form again.
Lucian's eyes darted busily, following the flow of mana.
Each seemingly casual movement on display was a treasure that could not be bought even with a fortune.
"Well? Do you understand now?"
"…The mana throughout the entire body remains constant."
"Yes. Exactly."
Seeing his quick comprehension, Aizen smiled in satisfaction.
"If you move all your mana around from one posture to the next, a considerable disconnect occurs with every action. After using a single technique, your movements inevitably become choppy. And that slight break in continuity is an opening large enough to get your head cut off in battle."
Lucian was left speechless.
He had believed that sword forms were about minimizing such openings—but to think that creating those openings in the first place was the real mistake.
It felt like he had been digging frantically at a rocky mountain, believing it to be a vein of gold.
No wonder knights snap into their stances so quickly.
"When using mana, you must maintain reinforcement of the entire body while still leaving leeway to direct it elsewhere. The key is not to pull mana away from what's already in use, but to continue your sword forms with the mana you've held in reserve. And then…"
Aizen paused and drew the manifested mana back in.
Unlike before, he assumed a proper, grounded stance.
"When control over mana supply becomes free, you can do things like this."
Paaang—
As he swung the sword, the sound of air bursting rang out.
Lucian was startled by the force, but what followed was even more astonishing.
Papang, pang, paaang—
What is this…?!
The sword was flowing.
For an ordinary swordsman, producing such sounds would require stopping the blade each time and swinging with brute force.
Yet Aizen was letting the sword flow continuously while still rupturing the air.
It was unbelievable even as Lucian watched it with his own eyes.
Like a dance, Aizen swung the wooden sword, then lowered his hand after completing the tenth strike.
"This is the sword you will be learning from now on."
Gulp.
Lucian swallowed hard.
And yet—Aizen had not even shown him the Lionheart Sword yet.
It was merely a demonstration of what happened when control over mana supply reached its extreme.
And yet, with nothing more than mana manipulation that could hardly even be called a sword form, it produced this level of power.
Once again, Lucian realized just how crucial the existence of a teacher was to a swordsman.
As he was still lost in admiration, a single question crossed his mind.
"…Then what happens if you use the Lionheart Sword while your control over mana supply is free?"
At the question, Aizen let out a hearty laugh.
"Naturally, it unleashes tremendous power. If possible, I would like to demonstrate it for you myself, but not here."
"Why is that?"
"This is a training ground shared by other knights, is it not? If I were to destroy it, His Grace the Grand Duke would scold me soundly."
That explanation alone was enough.
It meant that if used properly, it had power more than sufficient to utterly demolish the training grounds.
"Now, I've shown you the direction you should head in, so let us try applying mana control. We'll begin with transitioning between vertical and horizontal cuts."
After that, for three days straight, Lucian practiced nothing but vertical and horizontal cuts.
The key wasn't simply swinging the sword, but maintaining a constant level of mana throughout.
Hoo—
I thought this would be easy, but old habits keep tripping me up.
Though his body had changed, perhaps because his soul had repeated the same actions for so long,
the habit of stopping and striking from his previous life kept surfacing whenever he swung the sword.
It was almost a reflex, making it far from easy to correct.
"You've improved a great deal. You learn quickly."
"Thank you."
Despite Aizen's praise, Lucian couldn't bring himself to smile.
Having practiced sword forms for over a decade, he had believed he could perfect something like this in a single day.
Yet instead, he had spent three days just correcting bad habits he had ingrained.
I'll have to focus on swordsmanship for a while. If old habits slip out again, it'll be troublesome in more ways than one.
If he were merely clumsy, that would be one thing—but even in the wrong approach, Lucian's swordsmanship had become a coherent technique.
If he were to display techniques he supposedly hadn't even learned yet in front of others, attention would inevitably converge on him.
To avoid unnecessary suspicion, it was necessary to remake his body and habits entirely.
Well, maybe it's fortunate that I ended up at the level of a fast-improving beginner. If it had looked like I'd already mastered it, that would've been a real headache.
There was a world of difference between a genius grasping something instantly and an ordinary person who had perfected it through long practice.
An average swordsman might not tell the difference, but someone at the level of a Sword Saint would certainly sense the incongruity.
In that respect, Lucian's old habits had turned out to be an unexpected help.
"Let's move on to the next stage. This time, we'll coordinate our movements together—"
Aizen suddenly broke off mid-sentence and looked toward the entrance of the training grounds.
Before anyone even appeared, he frowned and spoke.
"What brings you here, Fourth Young Master?"
"As expected of you, Master. You noticed before you even saw me."
From beyond the doorway came a still-youthful voice.
It didn't seem he had been deliberately hiding—perhaps he had been in the middle of approaching—because his voice grew closer along with the sound of footsteps.
A moment later, a servant and a handsome youth about Lucian's age appeared.
"Joshua greets you, Master. And it's been a while since I've seen you as well, Brother."
There was only one person who could call Lucian "brother" while bearing the name Joshua.
That was Joshua ValdecK, the Grand Duke's fourth son.
Though called a younger brother, they had different mothers and were only six months apart—practically the same age.
As Lucian failed to react to Joshua's sudden appearance, Aizen stepped forward again and spoke.
"Yes, it is good to see you. However, we are currently in the middle of the Third Young Master's training, so please withdraw. If there is something you wish to discuss with this old man, I will come find you later."
"I did not come to see you, Master, but my brother. As the younger sibling who learned first, I wish to help my brother with his training. Might I ask for your permission?"
"Help with training?"
"When learning mana control, isn't there a process of lightly sparring with another person? The goal is to maintain a constant amount of mana even while using sword forms. If possible, I would like to serve as that sparring partner."
What utter nonsense.
Joshua hadn't learned nearly enough to be in a position to teach anyone.
And yet here he was, barging into the middle of a lesson to insert himself.
As Aizen let out a hollow laugh, Joshua quickly bowed his head.
"If I have offended you, I apologize. But I am quite busy in many respects, and this is the only time I have to speak with my brother. If possible, I would like to help with his training while using this opportunity to make up for the time we've missed."
In short, "helping with training" was nothing more than a surface-level excuse.
His real aim was to strengthen fraternal bonds by 'helping' his brother.
That, too, was absurd.
Who chooses sacred training time to build camaraderie?
And who does so by deliberately choosing a sparring match with swords?
His intentions were so transparent it was almost laughable.
Yet even so, Aizen found it difficult to refuse outright.
So this is… politics.
Though Aizen had lived obsessed with the sword, it wasn't as though he was ignorant of schemes.
He had never devised any himself, but in his youth he had been subjected to them often enough to grow sick of it.
Naturally, Joshua's intentions—those of a schemer still green—were completely transparent to him.
He never expected me to agree from the start. Is his real aim to keep requesting a spar until he's refused again and again?
The first few times, it would end with nothing more than a small dent to Joshua's pride.
Interrupting another's training was rude in itself, and there were plenty of reasons to refuse.
But if he continued to ask for a spar, and was refused over and over again…?
Gradually, the focus would shift away from Aizen and toward Lucian and Joshua instead.
He intends to brand the Third Young Master a coward.
Unless one charged in with murderous intent, this was a spar conducted under the supervision of a Sword Saint.
It wouldn't be an exaggeration to say there was no risk of injury—yet Lucian would refuse even that?
Joshua's rudeness in intruding on training would be overshadowed by questions about Lucian's courage.
Even more troublesome was that the pretext Joshua offered seemed, on the surface, perfectly reasonable.
Lucian had already had a few unpleasant incidents with the other two brothers.
But Joshua had almost no prior friction with him, and the gap in their swordsmanship didn't appear overwhelmingly large either.
As a sibling, Joshua was in a position where he could request a spar for the sake of camaraderie at any time.
"How troublesome."
If this had been nothing more than an insult toward Aizen himself, he would have refused without hesitation.
The problem was that this proposal was a political gambit aimed squarely at the Third Young Master.
If it was rejected, the one who would suffer wasn't Aizen—but Lucian.
It was just as Aizen's troubled gaze turned toward Lucian.
"Master, I know this is rude, but please accept my younger brother's proposal."
"What?"
"Even if we are in the middle of training, my brother has come all this way saying he wishes to share a moment of camaraderie with me. As his elder brother, would it not be shameful of me to refuse such a bit of childish affection?"
At those words, Aizen's eyes widened, while Joshua's face twisted sharply.
With a single sentence, Lucian had dismissed Joshua's actions as mere childishness while casting himself as the magnanimous older brother.
The Third Young Master's tongue is no joke either.
With wit like that, he must have had some other plan in mind when he accepted.
Aizen nodded calmly and stepped back.
"If that is the Third Young Master's wish, then so be it. However, this spar will end with this single bout. No matter how important fraternal bonds may be, private feelings cannot take precedence over training."
"Of course. Isn't that right, little brother?"
"Th–That is… correct."
Joshua forced a smile, his eyebrows twitching.
The nerve—after avoiding him until recently, to now speak as if he had raised him with his own hands!
Let's see if you can still talk like that after this.
Grinding his teeth, Joshua pulled away the cloth draped over the servant's arms.
At the sudden sight of real swords revealed beneath, Aizen's brow twitched.
"What is the meaning of bringing real blades all of a sudden?"
"It's only a single spar—using wooden swords would lack any sense of tension, wouldn't it? Since we have this opportunity, why not cross real blades instead? Neither my brother nor I have ever been to the battlefield, so it should be a valuable experience."
"This is outrageous…!"
Joshua's actions had crossed the line, and Aizen was furious.
Soiling training with political maneuvering was rude enough—now he was proposing real blades?
He couldn't even uphold the flimsy pretext he'd used to request the spar!
Just as a shout was about to burst from Aizen's lips—
"That sounds like a wonderful idea! Let's do it right away!"
"…?!"
Lucian's excited outcry cut both of them off mid-sentence.
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