Humans may have neurons, but there's no such thing as a "mind cell."
Despite its official name—"Neural Activation Agent"—the drug nicknamed Forbidden Medicine is in fact a powerful stimulant designed to forcibly awaken a person's Haki.
Specifically, Conqueror's Haki.
This ability, once awakened, not only bestows immense spiritual pressure but also strengthens the body, often curing minor illnesses on the spot—earning it a reputation as a miracle cure.
However, it only works on those born with the so-called "quality of a king."
Anyone lacking that rare potential will be overwhelmed by the drug's effects and die instantly.
Originally, this drug was created by the Celestial Dragons' ancestors to ensure they retained not just political but physical dominance for generations.
What they hadn't anticipated was that 9 out of 10 of their descendants lacked the very "royal potential" the drug required.
As a result, this miracle cure became a dangerous gamble—its failure rate overwhelmingly higher than success.
A powerful medicine? Undoubtedly. But only for the right person.
In desperation, Saint Budashiri gave it to a mere slave.
After all, if she was going to die anyway… might as well see what happened.
The moment the drug was injected, Hancock's body convulsed violently.
"Eek! What the hell is this?!"
"Hold her down! Nurses, now!"
As her body shuddered from the drug's effects, Saint Budashiri panicked and fled.
The doctors and nurses struggled to restrain her, but suddenly—
A massive, intangible pressure burst from Hancock's body.
All at once, the medical staff dropped unconscious.
That overwhelming pressure? Conqueror's Haki.
Simultaneously, Hancock's immune system was drastically enhanced.
Her raging fever and fatigue vanished as though they had never existed.
"Eek… I-I'm sure everything's fine…"
Muttering to himself, Budashiri cautiously returned—only to find his slave upright and alert, while the medical staff lay collapsed on the floor.
"Ehehe! See?! Told you it was a good medicine!"
Pleased with his "prescription," he jumped up and down like a child.
"Doctors, huh? Useless lowborns… drained their energy just trying to hold her still. Typical. Guess the great me had to do it myself~"
Kicking the unconscious staff as he left the room, Budashiri took no notice of the truth: they hadn't collapsed from exhaustion—
They had been knocked out cold by her Haki.
Satisfied with his success, he skipped off down the hallway, calling his father through a den den mushi.
"Daddy! You gotta come see the ship tomorrow! My human slave's gonna prove she's better than any giant's, I swear!"
...
"…And that's how it happened, nyon."
"W-Wait… So you're saying the reason big sis awakened her Conqueror's Haki was because of that pill?!"
"That's right, nyon. It's a good thing the Snake Princess possessed the qualities of a king. If it had been either of you, you would've died on the spot."
"But… how do you know all this so well, Nyon Grandma? Even we didn't know!"
"Thirteen years ago, after Rayleigh, Shakky, and I rescued you three, I personally treated the Snake Princess during her mental recovery. She told me the whole story herself. I'm guessing she didn't want you two to know."
As always, Granny Nyon and Sonia's personalities leaned toward the emotional, and the heavy tone reflected that.
But Rengoku, unfazed, focused on something else entirely.
"Hm. So her body now reacts to the sight of a Super Marine-Class warship by spiking a fever—that defense mechanism must've started back then."
"Exactly, nyon. After enduring that month of repeated labor and collapsing with a fever, her body internalized it: high fever = forced rest. So when her body saw the ship again, it reacted the same way. After awakening her Conqueror's Haki, she probably continued that work for two more months—burning out, recovering, burning out again… it must be engraved into her very cells by now."
"And this time, having forgotten about all that trauma, the sudden re-exposure triggered an extreme shock."
Sonia added her analysis calmly.
After a moment of silence, Rengoku looked at Granny Nyon and spoke up.
"You said her body recovered thanks to the pill she was given back then, right?"
"That's correct, nyon."
"In that case, what if I replicate the effect of the pill… by using Conqueror's Haki?"
"I… I suppose that's theoretically possible… but! Conqueror's Haki is said to occur in only one person out of millions! Wait—don't tell me… Are you a Conqueror, nyon?!"
Granny Nyon's voice trembled slightly as she looked at him with new eyes. Rengoku simply smiled.
"You could say that."
As he raised his right hand, crimson energy crackled around it like flames—Conqueror's Haki in its raw, controlled form.
"Unbelievable, nyon… To already have that level of precision… No wonder people say you're the next Admiral…"
"What do I need to do?"
"Hm… in theory, you'd need to inject her body with a similar quality and intensity of Conqueror's Haki. But your Haki needs to be stronger than hers—or at least more overwhelming in that moment. Otherwise, her body might not even respond."
"Like priming a pump. Got it. Don't worry—I never lose when it comes to guts and spirit!"
Rengoku's eyes burned with confidence.
"Alright then, nyon… Place your hand over her chest and pour your Haki into her."
"Understood."
He gently pulled back the coat he had earlier draped over her and placed his hand over Hancock's heart.
His fingertips pressed against the soft curve of her chest—but Rengoku's focus was absolute.
Even if any other man might've hesitated or faltered, in this moment, Rengoku's mind was filled with only one thing:
Saving her life.
"Pardon me."
He pressed his palm fully against her chest and began to channel his Haki.
It was like turning on a faucet—the torrent of Conqueror's Haki gushed from his hand and surged into her body.
"Kh… aaagh…!"
Hancock let out a weak moan, her body trembling as it reacted to the powerful energy.
"Big sis! Please hold on!"
Sonia grabbed her sister's hand, lowering her face beside her in desperation.
"Haah… haaaah…!"
"Just a little more! Hang in there, Boa Hancock!"
Rengoku poured every ounce of focus and willpower into his right hand, letting the full force of his King's Ambition flow into her.
Then—he felt it.
A second pulse.
An opposing force pushing back.
Boa Hancock's own Conqueror's Haki had awakened.
"It's coming…! Everyone, brace yourselves! A Haki clash is about to happen!"
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