Brain Domain Development

Chapter 9: 009. Brain Domain Development!

After breakfast, wearing nothing but a small pair of shorts, Mercer lay on the operating table on the second floor of the treehouse.

Breathing in sync with Kureha's finger presses, he described the subtle sensations of his breathing changes, and how Qi coursed through his entire body.

He could perceive a sensing force that seemed to pierce through his skin, flesh, and bones, scanning the changes in his body as he breathed.

Kureha's gaze was calm as she kept asking questions and occasionally jotting down notes. This feeling of being completely exposed under her scrutiny made Mercer deeply uncomfortable.

He finally understood how Garp and Kureha must have felt when he scanned them with Observation Haki.

It was utterly unpleasant!

After a long while, Kureha said flatly, "Alright, that's enough for today. But this kind of observation will require long-term monitoring."

"Still, you little brat are quite a treasure. Without a sound, your breathing has shifted to a whole new method. Interesting, interesting!"

She didn't press for the reason behind the change; Kureha only cared whether this result could be replicated.

Mercer got up from the operating table, put on his clothes, and looked around the room.

The walls were white, the items neatly arranged, and some of the experimental equipment looked very precise.

A few experiments were still ongoing.

"Doctor Doriel, have you made any breakthroughs in your Lineage Factor research?" Mercer asked.

Kureha: "Why?"

"Do you have any drugs for brain development here? You have ones for strengthening the body, but what about the brain domain?"

A glint flashed in Kureha's eyes as she thought about the books Mercer had been reading recently—all of them were conclusions and hypotheses about various aspects of the human body.

"The brain domain is a very mysterious research topic. Why are you thinking about this?" Kureha questioned.

Mercer thought for a moment. "After reading those books, I've been thinking: the human brain can generally only be developed to about 10% at most, and ordinary people usually only reach 3% to 5%.

According to the encyclopedia, past users of the Brain-Brain Fruit could typically develop their brains to about 20%, granting them abilities like photographic memory and learning a language in an hour.

The books also contain some hypotheses: when the brain is developed to a certain extent, or at a specific threshold, living beings might gain extraordinary abilities comparable to Devil Fruit users."

"And the physicist William Gallon once said—'Any wild fantasy of humanity has the potential to become reality.'"

Regarding the idea of brain development rate, there were many perspectives in his original world too. Now, after seeing those books, Mercer had made a decision.

"I want to try developing the brain's utilization rate. I want to see if increasing brain development could be a unique path of biological evolution. I want to see what a living being becomes when brain development reaches 100%."

In his original world, Einstein, the man with the highest IQ, was said to have only developed his brain to less than 15%.

That world was ordinary, with no manifestation of extraordinary power. But in this world, with all kinds of miraculous powers and resources, Mercer felt his idea wasn't just a fantasy.

Kureha narrowed her eyes. She had been researching the human body and Longevity Medicine for years. Now, at nearly 121 years old, her body was still in its prime, and she still had a long life ahead.

As for the brain, Kureha said flatly, "Not a bad idea. The human brain only accounts for 2% of body weight, but it consumes about 25% of the body's oxygen and 17% of its energy. The brain is a mysterious and unknown domain."

The human brain contains roughly 14 to 16 billion neurons, with trillions of connections between them—more than the known stars in the sky.

Unaware, one wouldn't think much of it; but once aware, it was startling. Mercer's perspective gave Kureha a fresh insight. As a doctor, her research on the human body might not be the best in this world, but she could certainly rank in the top two or three.

Regarding longevity, Kureha knew several methods and was constantly experimenting. But unconsciously, she had hit a bottleneck. So, why not try a completely new path?

Thus.

"Kid, brain domain development is no simple physical experiment. One misstep and you could become an idiot. And current medical conditions don't cover that field. Have you thought it through?" Kureha asked seriously.

For this Little Fellow, Mercer, Kureha had never treated him as an ordinary Child. After all, ordinary kids his age were either playing in the mud or eating and sleeping all day.

Mercer grinned. "Isn't Doctor Doriel here? I may not have the skills yet, but that doesn't mean you don't. You're still young, and I'm still small. We have plenty of time to research."

Hearing this, Kureha was momentarily stunned, then couldn't help but laugh and scold, "Little Rascal, you're thinking pretty big. You haven't even started yet, and you're already trying to boss me around. I haven't even said whether I agree or not."

Mercer's small face turned serious, a hint of nervousness creeping in. "Then, Doctor Doriel, you...?"

Seeing this, Kureha squinted her eyes and gave a faint, knowing smile. "If you want me to agree, you can. But you need to know, research doesn't start with just a snap of the fingers. Funding, equipment, materials—none can be missing.

Do you have a large sum of money? Do you have cutting-edge equipment? Do you have various experimental materials related to the brain domain? For brain development, just the materials alone—rare medicinal herbs, brains from various creatures, like large beasts or Sea Kings—all require great strength. Do you have that?"

Kureha laid the harshest realities bare before Mercer.

If these problems weren't solved, brain development research would just be empty talk. Even if they could still study it, it would only crawl at a snail's pace.

The purpose of saying this wasn't to crush Mercer's enthusiasm, but these were unavoidable hurdles. There was one more thing Kureha didn't mention.

Even if Mercer could gather all these conditions, exploring the unknown still carried the risk of failure.

Seeing the Aura emanating from Kureha, Mercer smiled. A faint trace of defiance flickered across his young face.

His voice echoed softly.

"I'm not even three years old yet, and I can already beat thirteen adults. In the future, I'll definitely be very, very strong. Money—I'll earn it. Equipment—Bear Cub and the Gulp-Gulp Fruit should be able to synthesize what we need. As for experimental materials, when I grow up, none of that will be a problem."

At this moment, Kureha stared blankly at Mercer, this child seemed to possess a unique, convincing charm about him.

"I must be crazy, actually letting a child talk me into this."

Kureha couldn't stop the corners of her mouth from curling up, letting out a cheerful "Heeheehee" laugh:

"Fine, I'll agree for now. But if you can't deliver later, I'll pull your pants down and spank your ass raw."

Mercer's face suddenly stiffened. He swallowed hard, looking exasperated. "By then I'll be all grown up. You'd really have the nerve to pull my pants down?"

Kureha looked down at Mercer and said flatly, "I raised you, changed your diapers, wiped your ass—I've seen everything there is to see and plenty I shouldn't have. I don't give a damn, so why should you?"

"Crude."

Mercer muttered under his breath.

Kureha glanced at him and said coolly, "Say that again?"

"No, nothing at all."

With nothing left for him here, Mercer went down from the second floor, took the starving Bear Cub, and headed straight out the door toward his vegetable garden.

Purple Bamboo Forest.

Two more days passed.

At nine o'clock that morning.

Kureha packed up and was about to head out. She said to Mercer, who was reading at the desk:

"I'm going to Drum Mountain's Royal Castle to collect the medical fees from a few days ago. Stay home."

Mercer turned to look at her. "Going alone is fine? Your fees are always sky-high. What if the king has bad intentions?"

Kureha raised an eyebrow and smiled faintly:

"In this country, I can go wherever I please. The old king won't do anything to me."

Seeing Kureha's confident demeanor, Mercer said, "Be careful, though. Bring a weapon. With millions of Beli on you, someone might try to rob you."

"Do I look like some weakling to you?" Kureha laughed. "Believe me, I could make you cry for mommy with one hand."

Mercer looked at Kureha, then suddenly said seriously, "Doctor~Mommy, safe travels!"

Her mouth twitched violently. Kureha laughed in exasperation. "You little brat, don't call me that. I'm not your mommy. Call me Doctor Doriel."

Still laughing, she walked out with a light step. Sensing with Observation Haki that Kureha had gone far, Mercer got up, put on his Laboon coat, and grabbed his weapon.

He left a note for Kureha.

Bear Cub, who had been waiting at the door, let out a "whine," clawed the door open, and slipped out first.

With a bamboo basket on his back, Mercer closed the door.

He put the key in its usual spot.

Stepping onto the crunching snow, accompanied by thin flurries, one human and one bear disappeared into the deep forest.

Though pandas are severely nearsighted, their sense of smell and hearing are exceptionally sharp.

Having been exposed to herbs since he was a few weeks old, Bear Cub had developed a knack for finding rare medicinal ingredients through constant exposure.

Bear Cub was clever. Along the way, using his keen smell and hearing, he never approached the territory of any dangerous creature.

The strategy was simple: sneak into the mountains quietly and make a fortune without a sound.

Mercer let Bear Cub take the lead.

Wandering through the deep snow forest, one herb after another was discovered. When he found suitable ones, Mercer picked them with practiced skill.

When he found something edible on the spot, he let Bear Cub have a snack. Drum Island wasn't large, but its resources were far from scarce. They encountered all kinds of creatures along the way.

Today's goal was herb gathering.

Nothing else.

If something truly blind crossed their path, it would just end up in Bear Cub's stomach. With the Gulp-Gulp Fruit's power, Bear Cub was no longer the bear he used to be. He ate anything, no questions asked.

The herbs they gathered were varied—some from trees, some from grasses.

The parts of tree herbs that weren't needed went to Bear Cub to fill his belly, and the same went for grass herbs.

Mercer was now a fully qualified medicine apprentice, and Bear Cub was a fully qualified "trash can."

The greatest strength of a Gulp-Gulp Fruit user? Definitely the fact that nothing ever upsets their stomach.

Occasionally, they ran into other hunters or herb gatherers on the mountain, but both sides avoided each other early on, sticking to the principle of live and let live.

Around five in the afternoon, Mercer and Bear Cub began their journey home. At one point, a rustling sound came from a bush not far ahead.

He set down the basket on his back.

Gripping the axe handle tightly, he swept his Observation Haki outward. A snow-white-furred Laboon burst out.

Rabbit in shape, bear in build, it charged forward on all fours.

About one and a half meters long.

Mercer's eyes narrowed.

"There's no other aura around. It's alone. Still a juvenile."

In the second before Laboon reached him, Mercer sidestepped, his right foot stepping back, taking in the wide-open jaws and sharp fangs. At the same time, the axe blade in his right hand slashed out diagonally.

Pshh!

Following the momentum of its charge, the axe blade cleaved through its neck, severing the windpipe. A spray of crimson blood splattered.

Mercer and Laboon passed each other. He swung the axe blade downward, flicking off the bloodstains.

The pose was cool.

Grinning smugly, Mercer turned to look at Laboon, who was convulsing in the snow, clearly not long for this world.

A few seconds later.

An irregular crystal the size of a grain of rice, shimmering with a mysterious luster, materialized.

[Obtained F-rank Soul Crystal x1]

So far, Mercer had collected two soul crystals, both grain-of-rice-sized.

Small animals like rabbits, or creatures below F-rank, couldn't yield soul crystals when killed.

The same went for things like small fish or shrimp.

Just like ordinary human children, their strength level didn't even reach the lowest F-rank.

With the soul crystal extracted, it meant Laboon was dead.

Mercer approached and examined it closely. The fur was glossy, pure white without blemish—good material for making clothes.

From a hidden pocket inside Laboon's fur coat lining, Mercer pulled out a surgical knife and began cutting along Laboon's chest midline.

The field of medicine was vast and complex, with many branches, including the specialty of surgical dissection.

Kureha was absolutely top-tier in medicine, not only in her own medical skills but also in teaching.

Thanks to the A-rank blessing [Breath], Mercer's control over his body became more adept, his mind calm, his fingers steady.

Using professional technique.

Without damaging the texture of Laboon's fur, Mercer skinned it completely intact.

The remaining carcass was gutted, the organs cleaned out with snow from the side. The clean innards were tossed to Bear Cub as a snack first.

He cut a few branches into skis and neatly arranged the prepared meat.

Bear Cub had eaten quite a few household items over the past few days, including rope and a saddle. Now, the rope materialized, connecting Bear Cub to the simple skis.

Bear pulling the skis.

Half an Hour later, at Drum Island's ski resort, Keister Town, in a tailor shop with a good reputation, Mercer and the shop owner reached an agreement.

Half the precious Laboon meat as payment, and the Laboon fur he'd brought would be made into a fur coat.

Come back in a month to pick it up.

He took the receipt.

Sitting on the skis, Bear Cub trotted out of town on all fours. By the time the sky was about to darken, Mercer finally made it home.

The lights in the treehouse were bright, meaning Kureha had already returned.

He opened the door, brought the herbs and the remaining half of the Laboon meat inside, and stored them properly.

From the kitchen came the sound of stir-frying. Kureha was cooking. Hearing the noise, she said, "Little Rascal, didn't I tell you to stay home today?"

"I went to gather herbs, and brought Bear Cub along for a snack." Mercer grinned. "Doctor Doriel, I got lucky today. I caught a Laboon."

The next second, Wielding a spatula, Kureha walked out with a dark face.

"A Laboon?"

New book on the road. Hoping all you big shots will nurture this little sprout. Follow-up reading, please!

Begging for recommendations! Begging for investments! Begging for follow-up reading!

PS: Soul crystal sizes by rank:

F: Grain-of-rice-sized.

E: Soybean-sized.

D: Broad-bean-sized.

C: Pigeon-egg-sized.

B: Chicken-egg-sized.

A: Goose-egg-sized.

EX Demigod: Human-head-sized.