"Only five minutes have passed," came Artoria's composed voice beside him.
"Though the first attempt doesn't need to last long, every fully trained knight under my command could endure at least an hour."
She added softly, "Itachi, even if you are still a child, you've been to the battlefield. You endured long marches under harsher conditions. You should be able to manage thirty minutes for your first time."
Only five minutes…?
Itachi's breathing quivered. He had never imagined that controlling his breath could be so difficult.
It was as if he were holding his breath—but forced to exhale that single breath not all at once, but in dozens of tiny fragments.
Even inhaling became a trial: he could not take a deep breath freely, only small, measured sips of air. He had to feel the oxygen slide down his throat into his lungs, to sense it exchange within his blood, flow, and circulate.
Doing this once or twice was simple.
Doing it hundreds of times, while maintaining perfect rhythm and control—was torment.
...
As the rhythm of his breathing accelerated the flow of his blood and energy, a strange, unbearable pain began to rise within him.
Yet it wasn't physical pain.
It was mental torture.
The pressure built—his lungs burned, his body screamed for air, and nausea, dizziness, and the primal urge to stop clawed at his mind.
In the dark corners of his awareness, distractions and temptations flooded in:
He wanted to stop the movement, to abandon control, to breathe normally again—to straighten his body, lie flat on the grass, and let himself rest.
But no.
Not yet.
Artoria had said it herself—this was not just a test of the body, but of the spirit.
And even through the haze, Itachi could faintly feel the changes happening within.
He was beginning to perceive the subtle movement of life energy in his body—the flow of blood, muscle, and vitality intertwining in response to his will.
The improvement was minute, yet real.
Seeing that faint glimmer of progress—the "light" within the endless darkness—Itachi's chaotic thoughts quieted.
If he could see even a sliver of result, he could endure.
—
"Ten minutes," Artoria's voice rang again.
This time, it did not disturb his focus.
"Fifteen minutes…"
"Twenty…"
Every five minutes, her steady voice cut through the silence like a metronome.
Sweat poured from his body, falling to the dirt in rivulets until the ground beneath him darkened.
Moments later, the moisture evaporated beneath the blazing sun, turning into a faint mist that rose around him.
His pale skin flushed faintly red, his body trembling, muscles flexing as the heat within him surged.
The blood coursing through him roared louder than any heartbeat—hotter, faster, stronger than when he had ever run or fought.
That same heat transformed into a shimmering haze around him.
In the sunlight, Itachi seemed surrounded by vapor, as though standing in the mist of a bathhouse—his outline hazy, his form shimmering between presence and illusion.
---
"Thirty minutes," Artoria said finally. She rose from the tree stump, her eyes filled with admiration.
"You may stop now."
But Itachi's voice came faintly, not aloud but through the bond of their minds.
"I don't think I've reached my limit yet. If the average knight under your command could endure an hour of this training, then I can do the same."
"They were grown knights, Itachi."
Artoria's tone softened.
"Your body, though far stronger than other children's, has not yet matured."
"I can do it."
His reply was quiet but resolute.
Seeing the unshakable determination in his spirit, Artoria did not argue further.
She sat back down, eyes fixed on the small, trembling figure before her.
She stopped keeping time.
He stopped asking.
Only the sound of controlled breathing filled the forest.
Minutes bled into hours until finally, his body reached its true limit—the point where every cell screamed for rest, where his blood, water, and stamina were utterly spent.
...
"One hundred and thirty-five minutes…" Artoria murmured, rising slowly to her feet.
"Over two hours. Remarkable."
Her admiration was genuine.
But before she could speak again, she froze.
Itachi didn't respond.
He staggered unsteadily, as though his body no longer obeyed his mind, stumbling forward in a daze.
"Too far…?" Artoria realized in alarm.
She had forgotten a critical difference—
Itachi was not like her. He didn't have dragon blood flowing through his veins, no inhuman vitality or regenerative ability.
Itachi dragged his exhausted body toward the nearby stream, each step a battle.
His lips were cracked and dry like sun-scorched earth, his throat parched as a dried well.
His skin burned with fever, his stomach clenched from hunger and emptiness.
But he knew exactly what his body needed.
—
Splash!
He collapsed knee-deep into the shallow water.
"Wait—!"
Artoria followed quickly, her voice laced with concern. But she could only watch—her spirit form unable to touch him.
Itachi ignored everything.
He cupped the cold water in trembling hands and drank greedily, gulp after gulp, uncaring whether it was clean.
Small fish and shrimp darted by—he grabbed and swallowed them without hesitation.
He needed energy, and he needed to cool his body down.
---
During training, his high temperature had been natural—the flow of blood and energy forced every organ to operate at full speed, maintaining internal balance.
But now that he had stopped, that same heat could damage him if it didn't dissipate quickly.
As his temperature lowered, Itachi lay back in the stream, letting the current wash over him.
Artoria stood at the bank, finally exhaling.
"For a first attempt, you pushed yourself too far," she said softly.
"You nearly lost consciousness. That's dangerous."
"I'm only a spirit—I can't help you physically. If you had collapsed here, no one would've been able to save you."
Feeling the chill of the water sink into his overheated body, Itachi replied calmly, eyes half-closed:
"I know my limits."
He now understood one thing clearly—Artoria truly had no experience training others.
But that didn't worry him.
Even if she lacked teaching experience, he knew how to measure himself.
No one understood his body better than he did.
Moments ago, though his body had nearly failed, his mind had remained perfectly lucid—
not in chaos, but in complete, unwavering calm.
And that, to him, meant victory.