At dawn the next day.
Robin and the three girls woke early from sleep.
Before they finished washing up and reached the deck, Master had already begun his daily morning training.
Seeing Kahn—whose strength was monstrous—train hard every day, the four felt both admiration and a surge of motivation.
If even Master worked this hard, they absolutely couldn't be the ones to drag him down and become his burden.
So the four did a light warm-up and began physical conditioning.
First stamina, then flexibility. When their bodies were burning hot, they started practicing the Navy's Six Powers.
Incidentally, Hancock had already learned two of the Six Powers, which shocked Robin deeply.
The two were Iron Body and Paper Art.
It hadn't even been half a month since they left the Sabaody Archipelago.
Hancock had learned two techniques of the Six Powers in less than half a month—what did that mean?
Know this: Robin had started training the Six Powers two years ago, yet she had only mastered Finger Pistol so far.
In other words, Hancock surpassed Robin's two years of effort in under half a month.
Seeing Hancock use Iron Body and Paper Art with her own eyes, Robin finally understood why Kahn had gone to such lengths—from the West Blue to Sabaody—to rescue the Boa sisters.
Hancock's talent was absurdly strong.
In truth, the reason she mastered two techniques so fast was that she had taken a shortcut.
Among the Six Powers, Iron Body and Paper Art are essentially half-finished forms of Armament Haki and Observation Haki.
With Hancock having mastered Armament and Observation at age twelve, training those two techniques was almost too easy.
As for the others, Hancock couldn't fast-track them.
Because her physique wasn't strong enough yet.
Among the four girls, the oldest now was Hancock at twelve, then Robin at eleven, then Sonia at ten, and Mary at nine.
If they grew normally, it would take at least six years, at most ten, before the four could truly support Kahn.
Kahn felt that was a bit too long.
So, after getting Hancock the Logia Lightning Fruit, he planned to give her a "boost."
By paying a small price, he could shave off years, even more than a decade, of effort.
By then, even if the Cross Family's core force numbered only a few, they would still be a presence no one could take lightly.
"Finally done."
Just as the four began training, Kahn smiled in satisfaction.
He clenched his right fist, and a black substance—visible only to those who had awakened Haki—covered it.
That substance was the manifestation of will itself, a power all strong fighters must have—Armament Haki.
When he'd patted Hancock's head, Kahn had secretly used his innate Observation to read her memories.
From Hancock's memories, Kahn smoothly obtained the Kuja's Haki training methods.
After passing those methods to Robin, Kahn began training Armament Haki to complete his last missing Haki.
From the start of training to success, Kahn had taken only three days.
An unbelievable speed, without question.
But Kahn felt no pride.
Just as he didn't dare claim the title of "Strongest Supernova in History," three days to learn Armament was not the fastest ever.
The record belonged to the Pirate King's son and Luffy's sworn brother—Portgas D. Ace.
How long did Ace take to master Armament?
One day.
Yes—just one day.
He awakened Conqueror's at ten years old and learned Armament in a single day.
Ace was a monstrous prodigy beyond reason.
If he hadn't eaten the Logia Flame-Flame Fruit and grown dependent on intangibility—
If he'd focused purely on martial arts and joined the Navy under Garp, Ace would have been the perfect heir to Garp's mantle.
Compared to Ace, Kahn's speed was nothing to boast about.
Of course, that was only for himself.
If Hancock knew Kahn had been unable to use Armament before this, the scene before her would have made her jaw drop.
But there were no "ifs."
Hancock had no idea that Kahn had gone to such lengths to save them not only to have the three sisters serve him, but also for the Kuja's Haki.
Not long after Kahn mastered Armament Haki—
After sailing through the night, the Grantaine finally arrived at Birka.
At the end of the cloud path stood a great gate into Birka, like the "Heaven's Gate" of Angel Island.
Passing through, they reached Birka's harbor.
After mooring the Grantaine at a pier, the five disembarked.
Seeing five Blue Sea people without wings, Birka's residents—like those of Angel Island—greeted them with enthusiasm.
The scene was almost satirically ironic.
If an islander had no wings, they were despised and bullied.
But Blue Sea people without wings were treated like "fathers."
No wonder that when Enel ate the Logia Lightning Fruit, he couldn't help but destroy this sky island.
If Kahn had been bullied for a decade or two and suddenly gained near-invincible power, he too would have retaliated.
Knowing why these people were so friendly, Kahn's group kept straight faces as they bought a local map, booked the most luxurious suite in Birka's largest inn, and began strolling the island.
On the surface, Kahn accompanied the four girls shopping.
In fact, he released his unique perception and searched for Enel's location.
A sky islander without wings was all too easy to find.
Enel was twenty this year, his features already much like they would be a decade later.
Soon, with perception that could cover several Birkas, Kahn found Enel.
The instant he found him, Kahn's lips curled slightly.
He could now be quite certain Enel had not eaten the Logia Lightning Fruit.
First, Enel was outside the city, not daring to approach crowded places, fearing Birka's residents would bully him.
Second, Enel's presence was weaker than that of the four girls.
A twenty-year-old adult whose aura was weaker than girls in their early teens—even a nine-year-old.
It meant Enel was a nobody among nobodies.