One Piece - Heaven Defying Comprehension!

"Ace, I'm stronger now," Vivi said as she activated her Sand-Sand Fruit ability. Her delicate form instantly transformed into sand, allowing her to appear beside Ace in the blink of an eye. With a playful smile, she threw herself into his arms, her voice filled with affection.

"Well done, Vivi," Ace replied, gently patting her head with a soft smile.

While Kaya was the most attached to Ace, Vivi was the most playful. Despite her courage in infiltrating Baroque Works as an undercover agent for Alabasta, she was still a seventeen-year-old girl who liked to show her softer side around her lover.

Giggling, Vivi's eyes narrowed into crescent shapes as she basked in Ace's praise and touch.

"But Nami is so strong," Raki chimed in, walking over with Nami by her side. "The three of us struggled to fend off her attacks head-on. The combination of Conqueror's Haki and her Thunder Fruit abilities is truly overwhelming."

Thanks to Ace's specialized training, which incorporated techniques from Amazon Lily, the girl's Haki had improved significantly. Each had gone through a transformation under Ace's Realm of Comprehension, developing both mentally and physically.

Before the Flame Emperor Incident, both Vivi and Raki faced the same challenge as Nami—their Haki was far too underdeveloped compared to their Devil Fruit abilities. Even wrapping their fruits in Armament Haki yielded minimal combat benefits. However, despite this, Raki, who had the Bird-Bird Fruit (Mythical Zoan—Suzaku), and Vivi, who had mastered the Sand-Sand Fruit, had grown immensely in power. Their combat prowess was now on the verge of Admiral-level, a step away from the peak power of the sea.

On this uninhabited island, they enjoyed the best training conditions. They followed Haki training methods specifically designed for women by the warriors of Amazon Lily. Their diet consisted of nutrient-rich Sea Kings, and Kaya's healing fruit ability, paired with her specially crafted medicinal baths, accelerated their recovery and growth. 

Most importantly, Ace, the most formidable Haki user on the seas, was their teacher. His Realm of Comprehension allowed them to progress faster than they ever imagined.

Even Rayleigh was astonished by how rapidly their Armament Haki had advanced. Vivi's Haki had reached the level of a Senior Vice Admiral of the Navy, while Raki's, due to her Mythical Zoan form, had reached the level of an Admiral candidate—comparable to a right-hand commander of the Four Emperors.

While they couldn't yet match a true Admiral in a one-on-one fight, the trio together could undoubtedly defeat one.

Among them, Kaya's progress in the Haki field had been the most remarkable. Her Armament Haki had become the strongest of the group. Before the Flame Emperor Incident, Kaya was known as a close-combat expert, skilled in both martial arts and Haki. But during the incident, her healing fruit awakened, revealing its true power, surpassing even the legendary Op-Op Fruit in terms of recovery.

Thanks to the combined effects of her healing abilities and Ace's Realm of Comprehension, Kaya's physical endurance improved at a terrifying pace. She could now harden her entire body with Armament Haki, forming an impenetrable armor she could maintain for long periods in battle.

Although Kaya's fighting style didn't yet match the legendary "Black Arm" Zephyr, a former Navy Admiral who relied solely on martial arts and Armament Haki, her strength had reached the level of an Admiral candidate—on par with the right-hand commanders of the Four Emperors.

However, Kaya had a unique advantage that Zephyr lacked: her unparalleled medical knowledge. Inheriting expertise from Crocus, the ship doctor of the Pirate King, and developing it further within Ace's Realm of Comprehension, Kaya's grasp of medical theory was unmatched in the sea.

This knowledge gave Kaya near-total control over her own body. She could push her physical limits to an extraordinary degree, unlocking strength that would normally remain untapped. For most humans, exerting all their strength would cause their muscles and organs to tear, but Kaya's precise control allowed her to avoid such damage while maximizing her power.

Kaya's Healing Fruit ability surpasses even the recovery powers of Zoan-type Devil Fruits after awakening. When she pushes her physical limits, unleashing her full strength, the force is so overwhelming that her muscles, bones, and internal organs tear and collapse under the strain. However, thanks to her Healing Fruit, she instantly regenerates, restoring herself to full fighting capability within moments.

This ability, combined with her powerful Armament Haki, enables Kaya to deliver devastating attacks in an instant. These life-threatening assaults allow her to tap into Admiral-level power. But this power comes with severe side effects.

While the Healing Fruit allows Kaya to recover swiftly from the physical damage caused by her extreme exertion, the pain of her muscles, bones, and organs tearing apart is intense. Even with her remarkable fortitude, Kaya can only withstand this process up to three times in a single battle. 

Despite his deep love for Kaya, Ace doesn't stop her from pushing herself. He respects her determination to grow stronger, knowing she endures this for his sake. In recognition of her efforts, Ace gave a name to her signature move: Black Flash.

Black Flash combines Armament Haki with her immense physical power, creating an attack so potent that it surpasses even the Navy's Six Kings Gun, a feared ultimate technique. When compared to old man Garp's Iron Fist, a famed Haki-based attack, Black Flash, when both are equally infused with Armament Haki, stands as the more powerful technique.

In terms of sheer martial strength, Black Flash represents the pinnacle of combat moves, as it is unleashed at the cost of Kaya's body tearing itself apart. Even Ace's Hakoku, a technique that draws power from his cells, pales in comparison to the raw force of Black Flash.

This devastating move is unique to Kaya. While Zoan Devil Fruit users possess extraordinary healing abilities after awakening, enabling rapid recovery, they cannot match Kaya's ability to override the body's self-protection mechanisms and control such extreme power without losing consciousness. 

As Ace described it, only Kaya, the "strongest medical theorist of this era," could perform such a feat. Her mastery over her body and the power of the Healing Fruit allows her to bypass natural limits, making Black Flash a martial technique on par with the strongest offensive Devil Fruit abilities.

Kaya was overjoyed when Ace named her move, so much so that she trained even harder. She now aims to use Black Flash in her next battle to prove her strength. Although she is known as the "Fallen Doctor" by the world, Kaya doesn't care much for the title, nor does she believe it fits her. How could she be considered "fallen" when fighting alongside Ace? In her view, it is the World Government that is corrupt.

Her goal is now clear: to change her title to "Black Flash" Kaya, cementing her place as a leader of the Entei Pirates' fleet.

Meanwhile, Raki approached Ace with excitement. Her wild nature, inherited from her Shandia roots, shone through as she stood beside him. Raki, who possessed the Bird-Bird Fruit (Mythical Zoan—Suzaku) form, had been growing stronger thanks to Ace's Realm of Comprehension. Her connection to her Devil Fruit was intensifying, and she now felt the will of the fruit itself.

Zoan Devil Fruits are known to contain a mysterious will, and the process of awakening these fruits carries great risk. If the user succumbs to the will during awakening, they risk becoming a mindless beast, losing their human form forever. As a rare Mythical Zoan, Raki's fruit had an even stronger will, which made her awakening particularly challenging.

Ace had previously cautioned Raki against attempting to awaken her powers, but now that her strength and Haki had greatly improved, the time had come to prepare for it. 

"When your Haki and physical strength reach the Admiral threshold, I'll help you awaken," Ace assured her, sensing her readiness with his Observation Haki.

The Bird-Bird Fruit (Mythical Zoan—Suzaku) form, like other top-tier Mythical Zoan fruits, not only bestowed special abilities upon its user but also enhanced their physical growth. Raki's body was becoming more powerful with each passing day, thanks to the Devil Fruit's influence. This was why, even in the same training environment, Vivi's Armament Haki had only reached the level of a Senior Vice Admiral, while Raki's had risen to the level of an Admiral candidate.

The immense physical strength granted by Raki's Mythical Zoan form, combined with her Haki, meant that she was on the verge of crossing into Admiral-level combat power. Once fully awakened, her Bird-Bird Fruit would allow her to stand among the top fighters of the sea, even without the need for Conqueror's Haki.

This level of power, granted by the top-tier Mythical Zoan Devil Fruits, was why such users could reach the peak of combat power in the seas once they fully mastered their abilities.

"Um."

After hearing Ace's words, Raki nodded in agreement.

"Compared to Nami, we still aren't strong enough. We have to work even harder," she said, clenching her small fists with a fiery determination.

"It's not that you're not strong enough; it's that Nami is just too powerful," Rayleigh responded, rubbing his forehead in exasperation. "If you aren't strong enough just because you didn't reach the Admiral-level threshold, then few in this sea could ever be called strong."

In truth, it wasn't that Kaya, Raki, and Vivi lacked strength—it was Nami's overwhelming power that made it seem that way. Ace, too, looked over at Nami, who had a sly smile on her face, understanding that her abilities had far surpassed expectations.

Raki and Vivi had already reached the level where they could unleash Admiral-level power. Their progress had been impressive, but Nami's power remained unparalleled. 

"Ace!" 

In the distant sea, Hancock, the emperor of Amazon Lily, stood on the deck of her ship, the Perfume Yuda, waving to Ace from the distance with a look of pure happiness on her face. Despite her responsibilities to Amazon Lily, Hancock regularly made the journey to deliver supplies to Ace and his crew on their isolated island.

"Hey, Hibehime, don't focus only on Ace. There's big news from the Marines!"

Beside her, Gloriosa held a stack of newspapers, her forehead damp with cold sweat, her eyes filled with disbelief.