The winter twilight stained the office of House Winterfeld in shades of amber.
Leonhard von Winterfeld, the Knight Commander, sat at his desk, wrestling with a mountainous pile of paperwork.
A sharp knock echoed through the room.
"Father, do you have a moment?"
"Yes, come in."
The door swung open, and his son, Klaus, stepped inside.
He had returned to the family estate for the Academy’s winter break. With his dark brown hair and refined features inherited from his mother, he looked every bit the aspiring knight, his posture perfectly straight. He was an excellent, prideful son—the man who would one day inherit the leadership of House Winterfeld.
"I have come to pay my respects before tomorrow’s departure."
"Hmph. A commendable attitude."
Leonhard leaned back in his chair, his eyes fixed on his son’s face.
His beloved son.
And yet, he couldn't ignore the fact that his own gaze now held a certain edge—a grain of doubt that hadn't been there before.
It had started as a minor sense of incongruity. When Klaus first returned from the Academy, Leonhard had asked him how his studies were progressing.
"Yes. I am spending my days most productively," Klaus had replied simply.
It was a flawless answer, but it felt wrong. The Klaus he knew would have immediately launched into a boastful account of his achievements.
Well, I suppose everyone has their quiet days, Leonhard had thought at the time.
But the discrepancies continued to mount.
During family meals, Klaus used to eat boisterously, constantly exclaiming how delicious everything was until Leonhard was forced to lecture him on the composure expected of a noble and a knight. This time, however, he merely sampled the food with elegant precision and offered a polite, graceful smile. "It was quite delicious," he had said.
Even when his younger siblings clung to him, begging him to play, Klaus had maintained that smile, but his movements felt scripted—as if he were merely performing a duty.
On the surface, there was no fault to be found. To any outside observer, he was the perfect "Young Master Klaus," the model son of a Knight Commander.
Yet, in the smallest, most minute details of his behavior, there were subtle flaws. There was no heat behind his actions, no fire in his soul. Leonhard felt an inexplicable, visceral sense of unease that he couldn't quite put into words.
He looked once more at the boy standing across from his desk, waiting to be dismissed.
Am I overthinking this? Has he simply matured?
Perhaps it was merely the melancholy of a father watching his child grow up. After all, the boy he had once dismissed as a sword-obsessed fool had suddenly excelled in magic, even taking the position of top student. It wasn't impossible for a person to change.
"If that is all, I shall take my leave."
As Klaus finished his greeting, another spark of intuition flared within Leonhard. It was tradition for Klaus to ask his father for a final sparring session before heading out, yet he hadn't mentioned it once.
"Wait, Klaus. Have you forgotten? We still have our pre-departure training to attend to."
"...Is that truly necessary?"
The look in Klaus’s eyes at that moment gave Leonhard the definitive proof he needed. Those eyes held the unmistakable will of someone looking down from above.
Is your sword even worth my time?
Leonhard's instincts as a warrior flared, sensing that silent condescension. His hands nearly trembled. The real Klaus, who worshipped his father and yearned to master his technique, would never—could never—think such a thing.
Who are you?
Suppressing the question echoing in his mind, Leonhard spoke.
"Naturally. A man of Winterfeld does not set out on a journey without first crossing blades."
"...I understand. I shall wait for you tonight at the training grounds, Father."
Klaus bowed and exited the office. Leonhard watched the closed door in silence, trying to settle his racing heart.
Night fell. Moonlight bathed the stone pavement of the training grounds in a ghostly blue.
Leonhard stood in the center of the yard, his favorite longsword gripped in his hand. Usually, they would use blunted practice weapons, but tonight, he had no intention of doing so.
In this moment, he would see into the very core of Klaus’s being.
As a Knight Commander, Leonhard had crossed blades with countless men. He took pride in his ability to read a person’s true character through their swordsmanship. If he found something definitive—something unforgivable—he was prepared to bring this blade down.
"Forgive my lateness, Father."
Klaus appeared in the moonlight. He frowned slightly when he saw the weapon in Leonhard’s hand.
"...A real sword?"
"The threat of death sharpens the focus. We will pull our strikes, but we play for keeps. Surely you’re capable of that by now?"
"Of course, Father."
Klaus did not reach for a practice weapon. He, too, drew a live blade. The two faced each other in the center of the grounds.
"Then... let us begin."
Silence fell between them. For a heartbeat, they simply measured one another's breathing.
Leonhard was the first to move.
He lunged forward, bringing his blade down in a heavy, overhead strike—a fundamental move, yet delivered with crushing speed and weight.
The sharp ring of steel on steel echoed through the night. Klaus’s sword met his father’s head-on, blocking it perfectly.
There was nothing wrong with the movement itself. The stance, the parry—it was exactly the technique Leonhard had taught him.
Leonhard disengaged, then stepped in again. He transitioned into a thrust. Klaus reacted effortlessly, evading the point while attempting a counter-slice. Leonhard slid his blade along his son’s, parrying the strike away.
His reactions are a bit fast—but not impossibly so for someone who has been training hard. His form and footwork are undeniably Klaus’s.
This was the swordsmanship Leonhard had drilled into him for over a decade. The movements, even the minor habits, were ingrained in the boy's very bones. This was the sword he had passed down to his son.
Was I wrong after all?
Leonhard wanted to believe that, but as they continued to trade blows, the hope began to crumble. Klaus’s "form" was right, but the spirit behind it—the heart of the knight—was alien.
Klaus’s sword had always been reckless. It had a youthful, desperate edge to it, the heat of a boy trying to reach the heights of the man he admired. He had always fought with a frantic energy, trying to absorb every lesson his father could offer.
The "son" before him lacked all of that.
In its place was a chilling composure. It was the sword of someone who was merely humoring an inferior. It was the sword of a superior being sizing up a subordinate.
It was an insulting way to fight. His beloved son would never wield a blade like that.
As their swords clashed again, the truth became crystal clear.
This man is not Klaus.
He was ninety-nine percent certain. To find the final one percent, Leonhard made his move.
He stepped in deep, raising his sword high for a massive overhead blow. Klaus’s eyes tracked the blade as it rose.
In that split second, instead of completing the swing, Leonhard dropped his weight.
He went for a low sweep.
It was a feint—pretending to strike high to draw the guard, then taking the legs. Klaus, being straightforward and impulsive to a fault, was notoriously weak against feints. He had fallen for this exact move every single time.
Every. Single. Time.
Leonhard had used it hundreds of times in their years of training, and hundreds of times, he had swept Klaus off his feet. He had lost count of how many times he’d seen his son land on his backside, red-faced and frustrated. It was a failure of instinct, a habit ingrained so deeply that no amount of lecturing could fix it. Against a normal knight, Klaus might see it coming, but he had never been able to handle his father’s lightning-fast execution of the move.
The last time he had hammered that lesson home was nearly a year ago. He didn't believe Klaus could have fixed it. At the very least, he shouldn't have been able to respond so perfectly.
And yet, with a perfectly calm expression, Klaus evaded.
As if he had known the move was coming from the very beginning, he lightly hopped over the sweep and backed away, maintaining his distance.
His son had simply improved?
Impossible. Habits like that aren't overcome so easily. In all his years of training knights, Leonhard had never seen a fundamental flaw vanish so completely.
Leonhard lowered his sword and turned a cold gaze toward his son—or whatever was wearing his son’s skin.
"Who... are you?"