It was clear that Nojiko and the others' impression of Kozuki Oden had been influenced, at least in part, by Ash's personal views.
Setting aside any bias against Wano for the moment, the title "invincible in the world" was never something Oden claimed himself. It was a label given to him by others.
Looking at the timeline, Oden returned to Wano around the year 1499 of the Sea Circle Calendar.
That same year, Gol D. Roger disbanded his crew shortly after reaching the title of Pirate King, then turned himself in. By then, Roger was 52 years old and suffering from an incurable illness.
Under those conditions, it was not surprising that Roger, long past his prime and weakened by disease, could not defeat Oden, who was 34 and at the height of his strength.
Edward Newgate, known as Whitebeard, was three years younger than Roger, making him 49 at the time. He was either at his peak or extremely close to it.
No reasonable person would believe Oden could defeat Whitebeard in that state, even if Oden possessed the rare ability to hear the Voice of All Things.
There was another important detail. Before joining Roger, Oden served as the Second Division Commander under Whitebeard. Their relationship went far beyond that of captain and subordinate.
Whitebeard would never seriously fight Oden, let alone decide a winner between them.
Without a true battle, there was no basis for victory or defeat. The title of "invincible" held little real meaning, and Whitebeard certainly would not care about such claims.
As for Big Mom and Kaido during that era, they were undoubtedly powerful, but still a step below the legends of the sea.
At best, their strength was comparable to figures like Silvers Rayleigh and Scopper Gaban, Roger's right and left hands, along with rising monsters like Douglas Bullet. Even then, it was possible they were still slightly weaker than Oden at his peak.
Many would argue otherwise, especially regarding Big Mom.
After all, she displayed terrifying strength even as a child, capable of destroying a Giant village during one of her uncontrollable hunger fits.
Kaido, on the other hand, belonged to the Oni race and was personally recruited by Whitebeard during the era of the Rocks Pirates. Later, he obtained a Mythical Zoan Devil Fruit, one of the strongest types in existence.
But that raises another question.
Are Giants truly that powerful?
The answer depends entirely on comparison.
Dorry and Brogy, the Blue and Red Ogres, are undeniably strong. When they combined their strength to unleash Hakoku, they could obliterate massive targets with ease.
Yet without time to prepare that attack, even someone like Mr. 3 could restrain them.
Marine Giant Vice Admirals appear imposing, but against top-tier fighters such as the Seven Warlords, they are often overwhelmed without much resistance.
Even Hajrudin, a Giant of royal lineage and captain of the New Giant Warrior Pirates, once fought as a gladiator under the Donquixote Family and was defeated by Monkey D. Luffy with a single punch.
In that context, the Giant race is not as dominant as it appears.
Big Mom destroying a village during a frenzy, especially with her natural Armament Haki, is not as extraordinary as it might seem.
Her truly absurd achievement lies elsewhere, giving birth to 85 children over 42 years.
That kind of record is unmatched, even beyond human standards.
Now, turning to Kaido.
The God Valley Incident occurred in 1486. At the time, Kaido was only 19 years old, still an apprentice in the Rocks Pirates. Despite his Oni heritage, his presence among that crew was not particularly remarkable.
During that battle, Charlotte Linlin obtained the Fish-Fish Fruit, Model: Azure Dragon, and casually handed it to Kaido.
With his natural strength and a top-tier Devil Fruit, his potential was undeniable.
However, after the fall of the Rocks Pirates, Kaido refused to join Big Mom and spent the next two years wandering alone, often being captured by the Marines.
Two years later, following MADS' announcement regarding the discovery of Lineage Factors, Kaido was captured again by the World Government and used for experimentation.
It was during this period that he met King. After escaping the facility together, they decided to form their own pirate crew.
A year later, major figures like Shiki, Whitebeard, and Big Mom established their own territories in the New World.
Meanwhile, Kaido and King continued drifting without a base. They eventually encountered a scientist known as Queen, formerly associated with MADS, but their first attempt to recruit him failed.
For years, the seas were dominated by the great legends.
Other powerful pirates such as Wang Zhi and Silver Axe controlled isolated regions, while powerful nations like Wano and Elbaf remained beyond Kaido's reach.
For five full years after forming the Beasts Pirates, Kaido held no territory.
Only after Kurozumi Higurashi approached him with a plan to seize Wano did he finally gain a foothold.
It was not a matter of ambition. He simply lacked the strength to take more.
Two years later, Oden left Whitebeard's crew and joined Roger. Around that time, Queen officially joined Kaido, bringing with him technological advantages tied to the World Government and Vegapunk's research.
With resources from Wano, Kaido began building a more formidable force.
Another year passed, and Oden returned home.
An important detail often overlooked is that Kaido and Oden were born in the same year.
However, Oden had trained under both Whitebeard and Roger, two of the greatest pirates in history. By then, his combat ability had reached the highest level of that era.
Kaido, in contrast, had no such guidance. The Rocks Pirates were not known for mentorship.
Receiving his Devil Fruit from Big Mom was already a stroke of luck. Shortly afterward, he was captured again, leaving him little time to develop his abilities before facing Oden.
Under those circumstances, Kaido's defeat was inevitable.
At that time, he was far from his peak. Otherwise, he would not have remained in the shadows while the great legends ruled the seas, only rising to prominence much later.
So when did Kaido reach his peak?
In Ash's view, it was during his encounter with Monkey D. Luffy two years after the Summit War.
If Luffy had not existed, Kaido's peak would have come even later.
Even by the year 1524, Kaido had yet to fully reach his limits.
From his own words, it was clear he valued Haki above all else.
Yet his mastery showed clear gaps.
His Conqueror's Haki was powerful, but inferior to that of Shanks. His Armament Haki was solid, but lacked refined techniques. His Observation Haki was unremarkable.
Advanced applications of Armament Haki, known in Wano as Ryuo, include techniques such as emission and internal destruction.
Evidence from the war shows that fighters like the Nine Red Scabbards could damage Kaido by using Ryuo.
Even Kaido himself was shocked, questioning whether they had mastered Oden's technique.
This suggests that his own Armament Haki lacked that level of refinement, especially compared to Luffy, who had already grasped internal destruction.
At that stage, Kaido still had room to grow in all three forms of Haki, and his Devil Fruit had not awakened.
Perhaps he avoided awakening due to the risk of losing his sense of self, a known danger with Zoan awakenings.
Regardless, he had not yet reached his full potential.
Unfortunately, in the twenty years after Oden's death, Kaido stagnated. He spent his time drinking, seeking death, and working with Donquixote Doflamingo to produce artificial Devil Fruits, creating a large number of flawed Zoan users.
Over two decades, his strength only rose to the level of aging legends like Whitebeard, alongside Shanks and Big Mom.
After years of conflict in the New World, eliminating remnants like Wang Zhi, the balance of power settled into what became known as the Four Emperors.
At that time, Shanks was only 33 years old.
Yet the difference between them was clear.
Back then, Kaido had resorted to underhanded tactics out of fear of Oden.
At the same age, Shanks stood at a completely different level.