Rasengan.
That was the ninjutsu Ian had chosen as his signature technique after ultimately setting Chidori aside.
The sphere of chakra swelling and spiraling within his palm carried my thoughts drifting back to years long past.
Back then...
He had still been very young.
With an innocent expression upon his face, he approached me and asked for something that left me speechless for several moments.
He wanted to learn Chidori.
I still remember that day with remarkable clarity.
Not because of the unusual nature of his request.
But because Ian had been far too young to wield such a dangerous ninjutsu.
I was worried about his body.
Chidori was not a technique that could be mastered through talent alone.
It demanded extraordinary chakra control.
Speed.
Precision.
And a body capable of enduring the burden of lightning coursing through every movement.
That was why I refused to teach it to him.
Instead, I instructed him to seek Father.
And exactly as I had expected...
Ian mastered it at a speed that bordered on the unbelievable.
Father praised him in front of me more than once.
He said that Ian's ability to learn was nothing short of a miracle.
Yet...
There was one problem that even Ian himself had failed to realize at the time.
Chidori was a Lightning Release ninjutsu.
And Ian...
Possessed no natural affinity for lightning.
At first, that weakness was nearly impossible to notice.
His talent concealed most of its shortcomings.
Yet as the years passed...
The more frequently he used Chidori, the more apparent the incompatibility became.
The technique gradually grew less efficient.
Its chakra consumption increased.
The hand seals it required created longer openings before each attack.
His body also demanded greater adjustments whenever lightning chakra surged through it.
None of it felt natural.
Father had recognized that truth long before the rest of us.
That was why he eventually instructed Ian to abandon Chidori.
Not because the technique lacked destructive power.
But because another technique suited him far better.
Rasengan.
A ninjutsu formed entirely from pure chakra without relying upon elemental affinity.
A technique capable of adapting to countless situations.
Whether in close combat or at medium range.
Far more versatile.
And most importantly...
Perfectly suited to Ian's calm and methodical style of battle.
Even I had to acknowledge the brilliance of that technique.
Chidori certainly possessed countless variations.
Its potential for growth was extraordinary.
Even so...
It carried a weakness that could never truly be ignored.
Its destructive area was relatively limited.
On the other hand, Rasengan...
Released an explosion of chakra with a far wider radius the instant it struck its target.
Its devastation spread far beyond the point of impact itself.
Even so...
When it came to killing an opponent, the difference between the two was surprisingly small.
Both Chidori and Rasengan were lethal ninjutsu.
The true difference had always depended upon the one wielding them.
And upon which part of the body was chosen as the target.
My gaze settled upon Ian once more.
The azure sphere of chakra continued spinning within his palm.
Pure chakra was being forced into countless simultaneous rotations.
With every passing second...
Its rotation grew denser.
More stable.
And vastly more dangerous.
I knew that technique all too well.
Just as the Rasengan neared completion...
Two bursts of white smoke erupted beside Ian.
Puff!
Puff!
Two Kage Bunshin, Shadow Clones, appeared at his right and left.
A diversion.
He intended to split my attention.
To separate me from the original body while creating an opening to strike.
For a brief moment, I saw the corner of Ian's lips rise.
His smile remained calm.
Gentle.
The same smile that always seemed capable of putting everyone around him at ease.
For some reason...
That sight reminded me of Karina.
Our younger sister.
The two of them rarely displayed much emotion.
Yet the impressions they left behind could not have been more different.
Ian's smile felt warm.
Comforting.
While...
Karina's smile...
I released a quiet sigh.
For some inexplicable reason, whenever I saw that girl smiling, I always felt as though she were mocking me.
Even though that was probably not the case at all.
Perhaps that was simply the natural shape of her face.
Or perhaps she did it deliberately.
No one truly knew.
Perhaps that was one of the many reasons why the two of us had always struggled to get along.
CHIRRRRRR!
Lightning erupted within my left palm.
The piercing cry of a thousand birds echoed throughout the training grounds.
Chidori.
Brilliant blue light danced wildly between my fingers.
Tiny arcs of lightning leapt into the air before converging once more into a single mass of extraordinarily dense, compressed energy.
For a brief moment, I glanced beyond the arena.
Lucas and Dorothea were still standing exactly where they had been before.
Neither of them had taken their eyes off our battle.
Now that I thought about it...
They were witnessing something that perhaps only a handful of people across the entire continent would ever have the opportunity to see.
A battle between two Shinobi.
To the people of this world...
We probably looked like Magician engaged in a life-and-death struggle.
Especially to Dorothea.
The young girl's lips were slightly parted.
Her sapphire-blue eyes had widened with pure, unrestrained wonder.
I could almost imagine the frantic beating of her heart within her chest.
Not merely because she was fascinated.
But because everything unfolding before her far exceeded what her eyes were capable of following.
Our movements were simply too fast.
To an ordinary person...
All they would likely perceive were fleeting shadows flashing past.
The occasional clash ringing through the air.
Followed by violent bursts of chakra that caused the atmosphere itself to tremble.
Lucas, however, was different.
His vision was far sharper.
Five years of Shinobi training had honed both his body and his senses.
He still could not follow every movement we made.
But at the very least...
He could grasp most of the flow of the battle.
And that alone was more than enough.
Mother's words drifted through my mind once again.
A person learns from what they witness. From observation. From experience. And from every mistake they see with their own eyes.
Little by little, those lessons shape them into someone stronger than they were before.
Unfortunately...
I was not Lucas's teacher.
Had he trained under my guidance...
I would have tempered him through trials far harsher than anything he had experienced thus far.
Every weakness would be stripped away.
Every hesitation would be crushed.
Until he became someone far stronger than the person he was today.
But...
I gave a faint shake of my head.
Forget it.
Lucas and I had never truly fit the roles of teacher and student.
If I were the one training him every day...
Things would end exactly as they had before.
My cousin would be the first one to give up.
Because this training ground was enclosed within a relatively confined arena, the ninjutsu we used also had to remain within controllable limits.
Earlier, Ian had used a Fire Release technique against Lucas.
Lucas responded with Water Release, followed by several other techniques.
Although the collision of those elemental forces had produced explosions powerful enough to shake the arena, everything had remained within safe boundaries.
The concrete walls reinforced by the Alchemists' Guild's artificial cement still stood firm without suffering any significant damage.
However...
That was only because his opponent had been Lucas.
Things would be entirely different if the battle were taking place between Ian and me.
Both of us had already reached the level of Jonin.
Our raw power existed on an entirely different scale.
Not to mention the countless ninjutsu we had mastered over the years.
Each one possessed the power to alter the course of a battle with a single technique.
I did not even wish to imagine what would happen if either of us truly unleashed an S-Rank ninjutsu.
Kirin...
My favorite ninjutsu.
Merely imagining it was enough to make me shake my head.
That heavenly lightning would not simply reduce every wall surrounding this arena to rubble.
The resulting shockwave would most likely shake a large portion of Brandenburg itself.
The city's residents would come rushing from their homes in panic.
The Aurors would undoubtedly arrive to investigate.
As would the senior members of the Alchemists' Guild.
There was no possibility that they would ignore an eruption of energy on such a terrifying scale.
That was precisely why...
This sparring match had boundaries neither of us was permitted to cross.
We fought with complete sincerity.
Yet we remained careful, ensuring that our battle would not descend into a catastrophe.
At least, I hoped so.
My gaze returned to Ian.
His two Kage Bunshin moved first.
They stepped forward almost simultaneously.
Then...
In the blink of an eye, both clones were already standing before me.
Without wasting even a fraction of a second, they launched into Taijutsu.
Their movements were astonishingly precise.
Not a single action was wasted.
One of them surged forward with a straight kick aimed directly at my abdomen.
The other circled to a different angle, seeking to steal my balance away.
I kept Chidori crackling within my left hand.
I did not dispel it.
With my katana gripped firmly in my right hand, I deflected the first kick.
Thud!
The impact rang sharply through the arena.
Before I could fully regain my footing, the second kick had already arrived.
This time from my left side.
Its target was my ribs.
The strike came so swiftly that it nearly landed alongside the first attack.
I immediately leapt into the air.
My body soared high above the ground.
Both kicks struck nothing but empty space beneath me.
But...
They did not stop.
The moment they realized their coordinated assault had failed, both Kage Bunshin shot skyward as well.
They gave me absolutely no opportunity to close the distance between myself and Ian's true body.
A quiet breath escaped my lips.
Remarkable teamwork.
As we hovered within the heavens for a fleeting moment before gravity reclaimed us, I sheathed my katana.
And our exchange of Taijutsu continued in midair.
Fists.
Elbows.
Knees.
Kicks.
They flew back and forth in an unending storm of violence.
Thud!
Thud!
Thud!
Each collision boomed through the air.
Until finally...
I saw an opening.
Without the slightest hesitation, my fist shot straight toward the abdomen of one of the Kage Bunshin.
Thud!
The clone instantly burst into a cloud of white smoke.
Puff!
Gone as though it had never existed.
One remained.
My hand immediately slipped beneath my clothing.
My fingers found what I had prepared long ago.
A shuriken.
I took aim at the remaining Kage Bunshin.
Then...
Throw!
The shuriken sliced through the air.
Ssssh!
Ian's clone landed first.
With a light, effortless movement, he tilted his body to the side.
My shuriken passed mere inches from his shoulder.
An easy dodge.
But...
That had never been my true objective.
The shuriken was nothing more than a distraction.
The instant the clone completed his evasive maneuver...
I was already there.
Shunshin no Jutsu.
The Body Flicker Technique.
I appeared directly before him.
The clone had not even been given enough time to draw another breath.
"Charlotte's Fist of Justice."
Thud!
My chakra-enhanced right fist slammed squarely into his chest.
Puff!
The Kage Bunshin exploded into white smoke.
Both clones had vanished.
Finished.
I had only just released a breath when Ian's voice descended from above.
"A swift and merciless elimination."
His voice remained as calm as ever.
"Big Sister is truly impressive. Especially when delivering Fists of Justice to my clones."
I immediately looked up.
There...
Ian hovered in the air.
His black hair fluttered gently beneath the embrace of the wind.
His gaze remained fixed upon me.
Within his right palm, the Rasengan continued to spin.
The brilliant sphere of azure chakra emitted an increasingly powerful hum.
Its rotation had become far denser than it had been only moments ago.
I immediately understood his intention.
A well-executed tactic.
By using his Kage Bunshin as distractions, he had forced me to spend valuable time eliminating them.
The instant my guard opened...
His true body descended from above.
A position that clearly favored him.
An aerial assault carried the momentum of gravity itself.
Its impact would be far greater than any attack launched from the ground.
If I made even a single mistake...
That Rasengan would strike me head-on.
The corner of my lips slowly curved upward.
The lightning dancing within my palm grew fiercer.
I tightened my grip around Chidori, forcing more chakra into the technique and dramatically increasing its output in a single instant.
"Very well... I shall stop holding back as well."
And then...