Billions of years ago, when his previous world and its people had still been young enough to consider themselves the 'Industrial Stage', they had finally put the right tools in the right place; microscale cameras, quantum-sensitive probes and all of that nanobot stuff… and made a shocking discovery on whales.
They had initially assumed the blowhole on their heads was a simple seal simply used to 'open for air' at the surface and then clamped shut underwater leaving the lungs always dry. They also thought this was how whales didn't drown.
'Hmph! Simple valve logic for simple minds.' Instinct interrupted, sounding unusually haughty.
Then, around the thirty-first century, they proved themselves wrong. The recordings had shown it clearly.
On deep dives, water 'did' enter the first part of the blowhole in small, controlled amounts as thin sheets of water slid along the inside, while the main valve that led to the lungs stayed tightly shut.
That outer part; the vestibule, wasn't just an empty tunnel, It was actually 'alive'.
They had discovered its insides weren't just plain skin but were covered with very thin, soft tissue full of tiny blood tubes, and on top of that sat a special slippery layer that held a very thin film of water instead of pushing it away.
'Here comes the kicker' Instinct quipped, to the 'micro-frustration' of Haki.
And as water moved over that film, blood flowed just underneath it making a little bit of oxygen from the water go into the blood and a little bit of CO₂ from the blood go out into the water. Breathing, or at least a partially sustainable one.
It was definitely not enough to let whales live underwater forever, they still needed to surface to take air, but it helped them stay down longer without drowning.
Their blowholes/nose were half-valve, half primitive gill.
This was the very obvious conclusion Haki had come to, but he took it up a notch and planned to apply it to himself.
To do this though, one's body would need to have been familiar with water, internally and externally.
'You're basically a fish, bro…' Instinct rose again.
'It took those idiots many years and a dozen research programs to figure that out,' Haki thought calmly, ignoring Instinct, as he prepared his mind for the 'Whale Breathing' process once again.
'I have this advantage, so my Adaptation should come faster.' Haki thought
'Oh. I see. But you said to me before 'don't think you're the only crazy one around here, watch me.'' Instinct brought up, then continued; 'But I only saw you doing something you were already familiar with. Drowning.'
Haki played along and let a single smirk crawl up his ten year old face. 'What happens when I combine both 'Whale Breathing' and the other imaginary method together?'
***
A month passed quietly. As his memories had integrated, he noticed that time had slowly become a background thing in his mind.
He had used the month to quietly make the 'Whale Breathing' an actual technique in his daily iterations, and on this day, he felt it. He was ready for his grand plan.
Integrating both methods together.
He started immediately as he sat cross-legged at the bottom of the basin, spine straight and hands resting loosely on his knees, his hair floated around his head like lazy shadows while the waterfall's roar pressed into his bones as always, but to him, it might as well have been silence.
'First, whale Breathing,' he thought. 'And then… Spiral.'
Instinct coldly hummed at the back;
'Showtime.'
***
First, he followed the familiar sequence he'd carved into himself over the last month.
He let his body rise slowly until his face broke the surface, and then he exhaled all the air from his lungs.
He proceeded to go underwater, in his usual position, then he inhaled. Water flooded him instantly as cold slid up his nostrils and into his nasal cavity, then down his throat in a single motion.
His body remained calm as water moved past his throat and into his lungs. His stomach, already used to being abused as a holding tank, especially during this past month, expanded again as some of the water passed further down. His abdomen tightened under the new weight, but compared to his earlier experiments, this was nothing.
He let the water fill him to that familiar point, just shy of the moment where his reflexes turned feral and his body tried to take control back by force.
Notably, iterations like this usually lasted tens of minutes, sometimes even an hour, due to his increased lung capacity.
He continued the whale breathing for a while, and then remained in his current state, while his mind moved on to the second part…
***
He had prepared the stone in front of him before hand as he knew he needed to maintain stillness.
*SHINGGGG*
He activated his spirit fully and his internal 'world' layered itself with reality… in his perception, of course.
The chipped imperfection in the stone glowed faintly in his eyes, his… 'Mind eyes', then a thin strand of 'mana' seeped out of it, drifting through the water and touching the space just before his nostrils.
Water was already there, physically, so both 'Mana' and water overlapped in his awareness for the first time.
'Enter,' he ordered.
Just as real water slid further into his lungs, imaginary 'mana' followed the path he had drawn in earlier 'mental iterations';
It flowed as usual, through nose then down the empty internal channel he'd made in his mind. It curved through a spiral path, four spirals to be specific, until it reached its center; his anchor, towards the point below his navel.
'Anchor.' He thought.
*DUM* *DUM*
Just as the 'mana' reached it, his abdomen felt packed and heavy, his chest was tight and his heart rate rose sharply, swifter than ever before. The edges of his vision began blurring into grey as small capillaries along his lungs were stretching further than they should, some already beginning to tear under the stress.
He let everything hold still at that point.
'Physical and Mental'
'Whale Breathing and Archimedean Spiral'
'What is the bridge between them?' he entered a strange state instinct would have called 'enlightenment' if not for the severity of the situation.
His success depended on whether his focus could remain steady.
'Whales let the water touch a part of their airway and taught that part to drink from it,' he thought calmly.
'They built a chamber, so I should use my lungs as the chamber and build the structure with my spirit… no, that's not enough.
'The bridge between them, their point of intersection, the place where the lines blur…'
'My Anchor' he 'looked' down, towards the location where his center was located and had only one thought; 'Continue.'
The 'mana' kept flowing once again, as it slowly compressed itself further and further. In his imagination, even, the stone where the 'mana' had been coming from was slowly deteriorating, and in his observation, this process was getting faster and faster…
The 'mana' twisted and folded, tossed and turned, upon itself, it compressed further and further as Haki increased his output of Focus onto his anchor, until…
*BANG*
One was a sound that happened in his mind; his imagination. The 'mana' had completely skipped processes and directly collapsed into something called a 'Point of Singularity.'
The second was the sound of his body failing to contain what his mind had just done.
For an instant, every part of him clenched at once. His ribs, his spine, limbs and even the tiny bones in his ears.
The pressure he'd forced into that single point at 'Anchor' didn't stay it, reflected back into his flesh.
Hairline cracks shot through his ribs as his spine bowed the wrong way. His joints were wrenched from their seats and his muscles tore loose from his bone.
The water around him lurched outward in a violent eruption as his small frame lost all its shapes at once, turning from a boy's body into a distorted, collapsing mass in a single heartbeat.
Even the basin felt it as the stone under him shuddered faintly and a ring of disturbed water raced outward from his position, slamming into the basin walls before rolling back.
And for that one moment, even as broken and unrecognizable as he was, he felt like the center of this little world, this little… pond. Everything moved because of him.
His expression, right up to the instant his face burst apart, had been calm.
He had imploded into a mass of flesh and blood…
'Hello, death.'
This was instinct's final thought before the total blackness of darkness.
***
[HEAL]
The change was immediate.
A 'capable enough' outside observer would have been able to see Haki being threaded into existence like woven threads, masterfully executed by a professional weaver.
He lay with his back against the floor, as his existence healed itself, and after it was done…
*SNAP*
His eyes snapped open immediately.
[Archimedean Series: Water Breathing]