When Khan defeated Kaido, he had Sonia and Monet join forces to land the final blow. Using the powers of the Paramecia-type Op-Op Fruit, they bypassed Kaido's world-class defences and implanted a subtle trick within his heart, ensuring that the "strongest creature in the world" would no longer pose a threat. In the process, they managed to draw a considerable amount of blood from Kaido.
By combining Kaido's bloodline factor with Bell's, Khan succeeded in creating his ultimate weapon: a flawless "Perfect Number One." Even after that, Khan still held a significant reserve of Kaido's blood.
After gaining access to Vegapunk's knowledge of artificial Devil Fruits and the replication of bloodline factors, Khan successfully replicated Vegapunk's methods, creating a second artificial Zoan fruit of the Fish-Fish, Mythical Beast, and Azure Dragon variety. However, like Vegapunk's original attempt, Khan's artificial Azure Dragon was also labelled a "failure"—not because of its abilities, but because of its appearance. Unlike Vegapunk's "pink dragon" form, Khan's creation was a different shade, resulting in a "blue dragon" with the same abilities as the original.
With the remaining Kaido blood, Khan went on to create nine more artificial Azure Dragons. Combined with earlier models from Punk Hazard and his own previous creations, Khan now possessed a total of eleven artificial Azure Dragons, each distinct in colour but identical in ability. However, all were considered "failures" due to their colours diverging from the original blue shade.
Khan decided that these eleven dragons should be consumed by his perfected warriors. Instead of granting the powers to his most powerful Perfect creations, he designated them for Perfect Eleven through Perfect Twenty-One. Specifically, he designed Perfect Eleven as a male while selecting upgraded female warriors from Amazon Lily to create ten Perfect models. These models combined the bloodline factors of these warriors with Bell's to create a perfected line of female combatants.
These newly perfected warriors, imbued with the powers of the artificial Azure Dragon, were given to Khan's top officers and his most loyal personal maids, transforming them into elite "dragon knights" who doubled as formidable bodyguards. Perfect Eleven, who had consumed the first blue dragon Khan created, was kept at Khan's side—partly as a tribute since Khan's favourite colour is blue.
However, the demands of Khan's maids kept growing. The ten dragons were simply not enough to satisfy them, so Khan promised that he would obtain more of Kaido's blood when he had the chance, creating additional artificial dragons for them.
Aside from Perfects One through Ten, each of the new Perfects from Eleven to Twenty-One also had a unique dual-Devil Fruit ability. Their second ability came from the Paramecia-type Paw-Paw Fruit, originally wielded by Bartholomew Kuma, whose special physiology and unique race made him an ideal template. This second ability was not acquired through creating more artificial Devil Fruits but rather through the bloodline factor replication technique, which allowed Khan to implant these powers directly into their bodies.
The Bloodline Factor Copy Fruit is a special serum that grants Devil Fruit abilities. Every time a "Perfect" creation uses the powers of the Paramecia-type Paw-Paw Fruit, the implanted serum is partially consumed. Once this reserve is depleted, the Perfect creation loses its ability and requires replenishment. This is the secret to how Khan's creations can wield dual Devil Fruit abilities.
In addition to enhancing his Perfect creations, Khan also managed to acquire Vegapunk's Seraphim series. Within the base on Slug Island, Khan discovered Seraphim, who was modelled after the Seven Warlords of the Sea. Since they were still incomplete, these Seraphim appeared in the child forms of the Warlords.
To become a Warlord of the Sea, each one had to provide a blood sample to the World Government—a basic requirement for the role back then, when technology was limited, and it was still the Age of Exploration. This allowed Khan to see child versions of figures like Hawkeye in these Seraphim, though a model of Boa Hancock was missing.
Khan couldn't help but admire Vegapunk's work. While the Seraphim lacked the raw strength of his own double-fruit, exoskeleton-enhanced Perfect creations, they excelled in human-like qualities. A Perfect creation could be commanded, but Seraphim were capable of acting with a lifelike autonomy that brought them closer to real humans.
For instance, although Khan used the Golden Lion's bloodline factor to create Perfect Eight, this creation could only match the Golden Lion's strength, not his unmatched dual-sword style. In contrast, the Seraph modelled after a young Hawkeye was capable of executing slashes with the mastery of a true swordsman—an inheritance of Hawkeye's own skill.
In bloodline factor research, Khan, despite his skill, was indeed a step behind Vegapunk. However, with Vegapunk's knowledge, Khan managed to upgrade Perfect Eight, enabling it to wield the Golden Lion's iconic dual-sword technique.
With the enhancements to the Perfect creations and the acquisition of the Seraphim series, the strength of the Cross Family surged. In terms of elite combat power, not even an alliance of the Four Emperors would rival the Cross Family. Now, the Cross Family boasts three powerful groups: Khan's personal maid squad, the dual-fruit-wielding Perfect creations, and the Seraphim series of lifelike artificial humans.
For lower-tier combat, the Cross Family commands hundreds of thousands of soldiers, each with a bounty-equivalent strength level of 80 million berries, through cloning and modification. Additionally, they possess two of the Ancient Weapons: Pluton, hidden in Wano, and Poseidon, represented by Shirahoshi.
With this power, Khan no longer feared a lack of firepower. Even in an era of chaos, where the entire world could become an enemy, the Cross Family could hold their position without fear.
Thus, after completing his Perfect creations and Seraphim, Khan finally left the underground base to tend to his maids and assess the world's current events, particularly monitoring the "Child of Destiny."
The Straw Hat Pirates, having left Fish-Man Island, coincidentally arrived at an island of fire and ice, the current "Punk Hazard." There, they defeated Caesar Clown, who was under Big Mom's protection. On Punk Hazard, they also encountered Momonosuke, who was en route to Zou but had been separated and brought to Punk Hazard for experimentation.
This marked the beginning of a new wave of change. Unlike in the original timeline, Momonosuke didn't eat an artificial Azure Dragon fruit; instead, Caesar had him undergo giantification, transforming him into an oversized child. Now five or six meters tall, with a baby face and large head, Momonosuke earned the nickname given by Luffy—the "Big-Headed Baby dragon."
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