Chapter 70: Itachi's Physiological Modification
"Law. Did you do something to me?"
Itachi's sudden question cut through the quiet hospital room.
Law, already exhausted from three days without proper rest, jolted upright.
"You noticed already? Itachi-san."
He managed a tired smile.
"Forgive me. I made that decision on my own."
Itachi could feel it now—as his pupil power slowly recovered, something had changed. His body's chakra was now connected to his eyes. The two flowed together, fed each other, moved as one.
Law continued.
"When I examined your body for treatment, I discovered something remarkable. You possess two distinct types of power."
He held up two fingers.
"One exists throughout your body. Another resides solely in your brain."
Itachi listened in silence.
"The recovery rhythms of these two powers were completely different. Your body's energy operated in a closed cycle—self-sustaining, efficient. But your brain's power... that was another closed cycle entirely. It drew energy only from itself, recovering independently of your body."
Law's expression grew more animated despite his fatigue.
"The gap between consumption and recovery was massive. So I used the Ope Ope no Mi's precise manipulation abilities to create new connections. I transferred blood vessels that supply your body's energy to also supply your brain."
He spread his hands.
"Now both systems recover at the same rate."
Itachi processed this.
"You're saying—through your ability—I can now use my body's energy to sustain my pupil power?"
"Exactly. It's not just consuming brain power anymore. Your entire system supports it."
Law stroked his chin thoughtfully.
"Master Itachi, correct me if I'm wrong—when you use that crimson giant, or the skeletal form, does it consume only your brain's power?"
"Yes. That's the power of the Mangekyō Sharingan."
"Let me guess—others in your family possess this power as well?"
Itachi's visible eyebrow rose beneath his bandages.
"How could you know that?"
Law nodded, satisfied.
"Then I can confirm it. Your family—the bloodline that carries your genetic inheritance—all of you share a genetic condition."
"A genetic condition?"
Law set Kikoku aside, leaning forward.
"Based on your confirmation, your reactions, and my surgical analysis of your brain structure—"
He ticked points on his fingers.
"Some members of your family inherit this powerful ability. But the gene isn't dominant. It's recessive. Not everyone manifests it."
"That's correct."
"But this power has a flaw. For those with this recessive gene, the brain's power operates on a closed loop—separate from the body's energy supply. That's the genetic condition."
Law's voice grew more clinical.
"This creates a disparity in recovery rates. Brain power restoration can't keep pace with physical recovery. Over time, excessive use without proper recovery causes damage."
Itachi exhaled slowly.
"That matches my experience."
Law continued.
"Left unchecked, those with this recessive gene who overuse their brain power suffer severe side effects. Brain damage accumulates. Various disorders develop—especially in the eyes, where this power manifests most strongly."
He paused for emphasis.
"If it progresses further, the brain exhausts itself completely. Brain death. Followed by physical death."
Silence filled the room.
Itachi lay motionless, absorbing this.
An outsider—a surgeon from another world—had unraveled the Uchiha clan's greatest mystery in a single operation.
"Currently, your genetic condition is... resolved." Law's voice carried professional satisfaction. "After modifying your energy supply, excessive consumption is no longer a concern."
"Wait." Itachi's brow furrowed beneath the bandages. "Before this, I exhausted my pupil power multiple times. By previous experience, such overuse should have caused blindness—severe side effects at minimum. But instead of deterioration, I felt my pupil power strengthen. What caused that?"
Law's expression grew serious.
"That's what I need to explain next, Master Itachi."
He leaned forward.
"Stop pushing your brain power beyond its limits."
"I observed this phenomenon in you. While I don't fully understand the mechanism, I'm certain of one thing—your emotions can stimulate additional power secretion. They raise your upper limit."
"Emotions?" Itachi's mind raced.
He remembered his father's words: No family loves more deeply than the Uchiha. But that love, when lost, transforms into hatred—and hatred awakens power.
Law picked up an empty IV bottle.
"Let me use an analogy. This bottle represents your eyes. Water represents your energy."
He held it up.
"You said your pupil power grew stronger. That means after using it, the bottle became larger—capable of holding more water."
"But—" He tapped the glass. "—every time you exceed your limit, you force all the water out through excessive use. That intense pressure cracks the bottle."
His finger traced an imaginary fracture.
"Each time you exceed your limit, another crack forms. Damage accumulates. Side effects emerge. Diseases develop."
He set the bottle down.
"When those cracks reach a critical point—the bottle shatters."
Itachi lay silent for a long moment.
Then—slowly—he exhaled.
"I understand."
He'd thought his increasing power was simple recovery. Special ability. Now he knew the truth.
The surge he'd felt on Fishman Island—watching Luffy's determination to destroy Noah, feeling emotions he'd never allowed himself to feel—that had triggered something. Changed something.
Law's words confirmed it.
"After my modifications, your energy supply is integrated. Recovery is normal."
His tone hardened slightly.
"I'm not saying don't use your power. I'm saying—don't exceed your limits."
Itachi nodded.
"I understand."
Law's expression shifted—a hint of the excitement he'd been suppressing.
"That crimson half-giant you summon... it's incredible. If you want to maintain that state longer, there are two ways."
"What ways?"
Law held up one finger.
"First—Life Return. It's a technique that grants conscious control over your body's functions. It could accelerate your recovery."
He paused.
"But that only affects recovery speed. It won't increase your brain's upper limit."
Second finger.
"Second—there's a Devil Fruit I know of. One that could compensate for any deficiency in your brain power."
(End of Chapter)
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