One Piece: The user of the Nen-Nen Fruit, who overturned the sea.

Beehive Island Laboratory.

Dr. Gracia had been notified by Roy in advance and had prepared the experimental equipment well in advance.

When Roy appeared at the lab door carrying the unconscious Blackbeard, Gracia pushed up his glasses, a hint of undisguised excitement flashing in his eyes.

"Is this the person with the special physical abilities?"

"right."

Roy threw Blackbeard onto the lab bed, and the seastone chains automatically tightened, firmly securing Blackbeard's limbs and torso to the bed surface.

"Marshall D. Teach, user of the Dark-Dark Fruit."

His physique can accommodate the power of multiple Devil Fruits—at least two.

I need to know why.

Gracia put on gloves and approached the lab bed.

The light illuminated the black-bearded man's fleshy face and the still-healing wound on his left shoulder.

The seastone chains emitted a cold, eerie blue light, continuously suppressing the Devil Fruit power within him.

When Blackbeard woke up, it took him a full ten seconds to realize that he wasn't having a nightmare.

His last memory was of the ball of light from Roy's fingertip striking his brow, and then all that was left was darkness.

He's awake now, but the world he's in is worse than a nightmare.

Above my head was a cold alloy ceiling, and below me was a hard, bone-deep metal bed.

His hands and feet were firmly secured by sea stone chains, the joints of which were welded tightly, without even a millimeter of looseness.

The walls around him were covered with all sorts of instruments he couldn't name, their indicator lights flashing a dim green and red light in the darkness.

An old man in a white coat was standing by the bed, holding a syringe in his hand, the tip of which gleamed coldly under the light.

"You're awake?"

Dr. Gracia's voice was so kind, so kind, that it sent chills down the black beard's spine.

"Don't be nervous, let's just have a blood test. It's a routine check-up, it won't hurt."

"Get out of my way! I'm a Shichibukai! Recognized by the World Government—"

Blackbeard's roar echoed through the laboratory, but Gracia paid no heed.

The needle pierced a blood vessel in the black-bearded man's arm, and dark red blood was slowly drawn into the syringe.

Blackbeard struggled desperately, tearing the sea stone chains apart with a rattling sound, but it did nothing but tighten the chains.

He could feel the power of the Dark-Dark Fruit still within him, but it was suppressed by the magnetic field of the Seastone, like a wild beast locked in a cage.

Gracia placed the drawn blood sample into the analyzer, pressed a few buttons, and the instrument emitted a low hum.

He adjusted his glasses and began recording data.

Who exactly are you people?!

What do you want?

I can give you money!

I'm now a Shichibukai!

Lao Tzu has an appointment letter from the world government—

Blackbeard's voice went from roaring to pleading, then to cursing, and finally to a near-collapse of incoherent ramblings.

He had schemed against and betrayed countless people in his life, but he never imagined that one day he would be lying on an experimental bed and being used as a test subject.

Roy leaned against the wall by the lab door, hands in his pockets, without saying a word the entire time.

His expression was calm as still water, as if everything before him was just a routine experiment.

Gracia took the data report off the analyzer, his brow furrowing slightly.

He drew another vial of blood, did another test, and then a third.

The three results were completely consistent.

"How is it?"

Roy finally spoke.

"Incredible."

Gracia put down the data report, took off his glasses, wiped the lenses with the corner of his shirt, and put them back on.

"Teach's body structure is completely different from that of ordinary people."

First, there are his cells—his cell activity is more than four times that of an average person, with a rapid division rate and strong self-repair capabilities.

Moreover, he has three hearts in his body, unlike any other race; he's practically an anomaly.

"Get to the point," Roy said.

Simply put, an ordinary person's body can only hold one Devil Fruit. Eating a second fruit will result in death, which will then lead to conflict.

When two demonic forces clash within the body, the body will be unable to withstand the conflict and will collapse.

However, Teach's body lacked this rejection response, allowing him to possess multiple Devil Fruit abilities within him due to the presence of three hearts.

Gracia picked up another data report,

"More importantly, the gene sequence."

Teach's genes contain a large number of segments that are not normal human genes. After comparison, these segments matched the genes of three completely different organisms.

Simply put, this guy is a mixed-race individual, with multiple bloodlines forming a unique balance within him.

This balance makes his body a natural energy reservoir.

Roy nodded. "Continue."

"And there's the most crucial discovery."

Gracia walked to the lab bed and pressed a button on the wall.

A pale blue scanning beam descended from the ceiling and slowly swept across the black-bearded man's entire body.

The screen displayed a diagram of the black beard's internal structure, with bones, blood vessels, and internal organs layered on top of each other.

Gracia tapped the display screen, zooming in on the chest area.

"Look here."

The structure inside the black-bearded man's chest cavity was clearly reflected on the screen.

It's not one heart. It's three.

The three hearts are arranged in a perfectly regular triangle within the chest cavity, each beating independently with a different rhythm.

Roy straightened up from the wall and walked closer to the monitor. He looked at the image of the three hearts, and a slow smile appeared on his lips.

That smile wasn't one of excitement, but rather the relief that came after a mystery that had troubled him for years had finally been solved.

"Three hearts," Roy said softly.

"Yes. The continuous operation of three hearts makes his blood circulation speed more than three times that of an ordinary person."

Their energy recovers extremely quickly, and their mental strength is therefore exceptionally powerful.

Based on my calculations, he probably doesn't need sleep to recover his strength at all.

"No need for sleep."

Roy repeated the word and looked at the black-bearded man who was strapped to the lab bed.

The man with the black beard trembled after being scanned by the beam of light, muttering something unintelligible.

"He was able to remain silent and unsuspecting on the Whitebeard's ship for over twenty years."

Whitebeard was a shrewd man, and Marco was not one to be easily fooled.

But Teach managed to hide it right under their noses for decades without anyone noticing anything amiss.

This forbearance is partly due to cunning and partly due to the advantage of not needing to sleep.

If a person has a few more hours of activity time each day than others, over the years, they can accomplish so much.

Blackbeard's body shuddered violently.

Every word Roy said peeled back the layers of his deepest secrets.

He thought these secrets would never be known to anyone; he thought he had hidden them well enough.

But to Roy, he was nothing more than a specimen placed on a lab bed.

"Thief...thief..."