As morning arrived, the soft light of dawn filtered through the cracks of their home, touching Arthur's face as he opened his eyes.
He had maintained the Total Concentration Breathing throughout the entire night, something that should have been impossible for a normal person to sustain. But Arthur was far from ordinary.
His lungs had been overdeveloped through years of swimming and deep-sea diving alongside Rayleigh, hardened by the constant strain of pressure and endurance.
For him, breathing in rhythm for hours on end was as natural as moving his limbs.
Without wasting any time, Arthur stood up and stepped outside. The air was cool, carrying the scent of salt and morning tide.
He filled his lungs to their limit, then exhaled slowly, feeling the air circulate through his entire body.
His breathing was stable, heavy yet controlled, and every inhale brought a faint tingle through his muscles.
Wanting to test his limits, Arthur made his way to the shore and dove straight into the sea.
The cold water embraced him immediately, but he paid no attention. Using his breathing as a guide, he began to dive deeper and deeper, letting the immense pressure of the ocean squeeze his body.
For most people, descending to such depths would mean certain death. Even for Arthur, it was once a place he could barely endure.
His usual training ground rested around two thousand meters beneath the surface—a depth where even sunlight could no longer reach, and where the crushing pressure would collapse steel.
Yet this time, as Arthur descended, he felt no strain at all. His lungs expanded effortlessly, his body remained calm, and the pressure that once threatened to break him now felt insignificant.
It was as if the very act of mastering his breathing had redefined his physical limits. Realizing that, Arthur decided to push himself even further.
He swam downward, deeper into the darkness, until he reached the point where his eyes could no longer see.
Even with his sharpened senses, it was complete blackness—a place where sound and light ceased to exist.
For a moment, he hovered there, suspended in the silent void, before beginning his usual routine.
Arthur started to move, swinging his arms as if holding an invisible sword. Each swing was resisted by the water's pressure, every motion feeling as though he was lifting an entire mountain.
His movements were precise, practiced, and deliberate. He imagined his father standing before him once again, their swords clashing endlessly as they had so many times before. Down here, in the heart of the sea, his imagination became his training partner.
Then, something massive stirred in the darkness. A colossal Sea King—large enough to swallow a ship whole—emerged from the shadows.
Its single eye gleamed faintly, and its enormous jaws opened toward Arthur. In that brief moment, Arthur felt an instinctive calm, not fear. A sudden spark of inspiration flashed in his mind.
He concentrated, letting the flow of the surrounding water guide him. His body moved in sync with the sea currents, threading through the dark water as if becoming part of it.
With that movement, he swung his arm in a fluid, circular motion—his imaginary sword slicing through the resistance of the deep.
The impact was instant. The Sea King convulsed as the force of Arthur's strike connected, knocking the creature unconscious with a single blow.
For a few seconds, Arthur simply stared at it, feeling the weight of the moment. Then, he began his ascent, gripping the Sea King by its tail as he pulled it upward with steady, measured strokes.
While rising toward the surface, he couldn't help but smile faintly. The experience had given him inspiration—a realization of how his breathing could flow and merge with the natural movement of the world around him.
He now had the foundation for his own breathing style and swordsmanship.
'I can't wait to put it into practice,' Arthur thought, his expression calm but certain.
When he finally broke through the surface, sunlight greeted him, glittering across the waves.
He hauled the massive Sea King toward the shore, dragging it behind him as though it weighed nothing. Near the coast, Rayleigh was already sitting by the water, a bottle in hand as usual.
"What a huge catch you've got there, Arthur," Rayleigh commented, raising an eyebrow as his son approached. He smiled, but his sharp eyes noticed something else—Arthur's breathing. It was different now, deeper and more refined, as if each breath carried strength within it.
There was also a subtle shift in Arthur's presence, something Rayleigh couldn't quite define. Even with all his years of mastery in Observation Haki, he couldn't read the boy's aura clearly anymore. It was as if the faint presence of a child had vanished, replaced by something hidden and potent.
"What happened to our visitors?" Arthur asked, glancing toward their home.
"Your mother already contacted your Aunt Nyon and Aunt Tritoma," Rayleigh replied, taking a sip from his bottle. "They'll come to pick up the girls in about a week. There are still too many Marine patrols around for now."
Arthur nodded slowly. "What a sad situation. That kind of experience isn't something I'd wish even for my worst enemies."
Rayleigh nodded in agreement, his tone soft but serious. "That's why you have to be strong—strong enough that no one can ever put you in a position like that. And strong enough to protect those you care about. You must become stronger than even me."
Arthur met his father's gaze and nodded, firm and respectful. "Of course, Father."
Satisfied, Rayleigh smiled faintly, then in one swift motion drew his sword. With a single clean strike, he cut the enormous Sea King into several pieces, each portion perfectly even.
"Let's not waste breakfast," he said casually, as the waves carried away the last remnants of the creature's roar.
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While waiting for the food to finish cooking, Arthur sat down near the window and closed his eyes, entering a quiet state of meditation.
His breathing slowed, steady and deep, as he began to recall the sensation he had felt earlier—the stillness of the abyss beneath the ocean, that endless darkness which swallowed even the strongest light of the sun.
He remembered how the sea moved with a silent rhythm, how every current below seemed to twist and flow without resistance, how it consumed and yet maintained balance.
As those memories resurfaced, Arthur began to align his breathing to that rhythm, matching the flow of his lungs to the invisible pulse of the sea.
Each inhale drew in not only air but also a strange calmness, a quiet strength that seemed to rise from the depths of his own body.
Each exhale carried weight, a pressure that expanded outward, subtle yet suffocating, like the crushing force of water pressing from all sides.
Bit by bit, he started shaping his Total Concentration Breathing into something new—something that reflected the ocean itself.
The deeper his focus went, the more his consciousness sank, as if he were descending once again into that boundless black sea.
There, within that mental abyss, he felt a strange connection, a faint pulse that seemed alive, whispering its rhythm into his lungs.
Then, without realizing it, Arthur's body began to move on its own. His arms flowed with slow, fluid motions, rising and falling in rhythm with his breath.
His stance shifted naturally, stable but never rigid, his movements mimicking the steady advance and retreat of ocean waves. Each gesture carried an undercurrent of crushing power, restrained but ever-present.
He could feel the technique taking form—an expression of calm destruction, of silent depth and unstoppable force.
His breathing was no longer just a method to strengthen the body; it was becoming an extension of his very essence, something born from the abyss and molded through will.
Arthur opened his eyes slightly, the faint glow of focus still in them, and continued to move without thought or hesitation. Every motion flowed into the next, unbroken, as if guided by the ocean itself.