Rosen was momentarily stunned, then quickly focused. This was probably the world's foremost authority on Devil Fruits speaking. If he missed this chance, where would he find another?
"Devil Fruits are mysterious, truly mysterious. I've researched them for years but still haven't fully uncovered their origins. However, I have confirmed one thing: the so-called curse of Devil Fruits is not actually a curse." The Doctor's expression grew serious.
Not a curse?
"Correct. From a scientific standpoint, Devil Fruits are a type of peculiar lifeform. When a person eats one, they form a symbiotic relationship with it. The fruit's power resides within the host's genes, altering the host's life structure while simultaneously receiving the host's life force to sustain its own existence. This is why ability users cannot swim. Seawater doesn't negate their abilities; it weakens the symbiotic bond, causing fatigue. Seastone has a similar effect." The Doctor explained unhurriedly.
"Symbiotic lifeform..." Rosen mused. "So the fruit itself is alive? That would explain why abilities reappear after the user's death."
"Exactly. It's alive. Its life cycle is peculiar, but it is undoubtedly a form of life. It can choose its host, and after the host's death, it can regenerate elsewhere. The exact mechanism remains unclear to me." The Doctor's eyes sparkled with the light of a scholar facing an unsolved mystery.
"Then why do Devil Fruits grant such diverse powers? Some are elemental, some are animal-based, some are supernatural..."
"This involves the essence of the fruit. My research suggests Devil Fruits are actually fragments of rules from some ancient era. They carry vestiges of past wills and powers. When symbiosis occurs, these rule fragments manifest through the host's body." The Doctor's tone grew deeper.
"Rules?" Rosen thought of his own Suna Suna no Mi. "Controlling sand, turning into sand... was this a fragment of some rule?"
"Yes, rules. For example, your Sand-Sand Fruit likely carries a fragment of rules related to aridity and erosion. Paramecia types are more complex, possibly combinations of multiple rule fragments. As for Zoan types, they are the most peculiar. They carry not just rules, but the will of ancient creatures." The Doctor looked meaningfully at Rosen.
"The will of ancient creatures?" Rosen thought of Chopper and the rumored mythical Zoan fruits. "That would explain the enhanced physical abilities and the existence of Awakening."
"Indeed. Awakening is when the symbiotic relationship deepens to the point where the host can further tap into these rule fragments. For Zoan types, Awakening might even mean communicating with the ancient will within the fruit. This is both a gift and a burden." The Doctor sighed.
Burden?
"Because the stronger the will within the fruit, the more it affects the host. If the host's will is insufficient, they might be consumed by that ancient will, losing themselves. This is the true danger of Devil Fruits, not the inability to swim." The Doctor's tone grew grave.
Rosen was silent for a moment, digesting this information. It aligned with some things he'd observed but explained them on a deeper level. "So if someone eats a fruit with an extremely strong will, they risk losing themselves?"
"Precisely. But conversely, if the host's will is strong enough, they can fully harness the fruit's power, even surpassing its original limits. This is what we call the pinnacle of ability use." The Doctor nodded.
Is there a way to resist that ancient will's erosion?
"There is. Strong willpower itself is the best resistance. Additionally, Haki, especially Conqueror's Haki, can effectively counteract these spiritual influences. This might be one reason Haki users generally make better ability users." The Doctor stroked his chin.
"So what about artificial Devil Fruits?" Rosen suddenly thought of Kaido's army.
"Artificial fruits..." The Doctor's expression darkened. "They forcibly replicate the rule fragments, but imperfectly. The ancient will within is chaotic and incomplete. Those who eat them either cannot control the power or are easily consumed by the chaotic will, losing reason. This is why most artificial fruit users are unstable."
"So your original research wasn't for this?" Rosen probed.
"No. My initial goal was to understand the nature of life, to find ways to improve human life, not create weapons or armies. But..." The Doctor's voice trailed off, bitterness on his face.
"But the World Government had other plans," Rosen finished.
The Doctor didn't deny it, only sighing. "I've been a fool, thinking I could guide this power for good. But power itself has no will; it's how it's used that matters. Unfortunately, I'm no longer free to choose how my research is used."
Rosen looked at the Doctor, seeing not an evil genius but a trapped man. "If you had the chance, would you leave here?"
"Leave?" The Doctor was startled, then shook his head with a wry smile. "Impossible. The World Government watches me too closely. Even if I escaped, they'd hunt me forever. And my research... some of it, if left unfinished, could cause greater disaster."
"What if someone offered you protection?" Rosen's eyes narrowed slightly.
"You? The Doctor looked at Rosen appraisingly. You're strong, that's clear. But the World Government's full might is beyond what any individual can withstand. Even the Emperors only maintain a fragile balance, not true opposition."
Rosen didn't argue; the Doctor wasn't wrong. But he had another question "What about the Gum-Gum Fruit? Have you researched it?"
The Doctor's expression flickered almost imperceptibly, but Rosen caught it. "That fruit... is special. Very special. I've tried to obtain samples for study, but it seems to avoid my reach deliberately. Every time I get close, it vanishes. Almost as if it has a will of its own, avoiding being studied."
"A will of its own?" Rosen's mind raced. The fruit that Luffy ate, the one the World Government supposedly sought for centuries...
"Yes. Among all Devil Fruits I've studied, the Gum-Gum Fruit is the most anomalous. Its rule fragments are incredibly ancient, possibly from the Void Century. But every attempt to analyze it fails." The Doctor looked troubled, like a scholar stumped by an intractable problem.
Rosen filed this information away carefully. This was more valuable than anything he'd imagined.
The Doctor finished writing and handed Rosen several sheets of paper. "Here are the serum formulas and some supplementary research. Whether they help your people depends on their individual conditions."
Rosen took them, scanning briefly before tucking them safely away. "Thank you, Doctor."
"Don't thank me. I'm merely trying to atone for sins I enabled." The Doctor's voice was heavy.
"One last question." Rosen stood, preparing to leave. "If you could start over, knowing what you know now, would you still research the Blueprint of Life?"
The Doctor was silent for a long moment. "I... don't know. Knowledge itself isn't evil, but once discovered, it cannot be undiscovered. Perhaps I'd research it still, but guard it more carefully, ensure it never falls into the wrong hands."
Rosen nodded. "That's the difference between you and them." He moved toward the window, then paused. "The commotion outside won't last forever. I need to go. If we meet again, Doctor... I hope it's under different circumstances."
"Wait." The Doctor called out. "You still haven't told me who you really are."
Rosen turned back, a faint smile under his scarred disguise. "Someone who hopes this world can change." He leaped out the window, sand swirling to catch him, vanishing into the night.
The Doctor stood alone in the silent room, surrounded by unconscious guards. He looked at the papers on his desk, then at the window, murmuring, "Change the world... perhaps you're the one who can."
Outside, alarms still blared, but Rosen moved like a shadow through the chaos. He found Hathaway exactly where planned, a small warship secured and a guide bird caged.
"Success?" Hathaway asked, noting his expression.
"More than success." Rosen's eyes gleamed. "We got answers I never expected. Let's go. Before they realize the diversion was just that."
The warship slipped away from Peak Island, swallowed by the mist, leaving behind a base on high alert and a scientist with much to ponder.
(End of Chapter)