Everyone has something they're afraid of, and some things exist almost like psychological shadows.
For Yamato, Kaidou is her psychological shadow.
She's no longer the same as she was before; the days when Kaidou could easily deal with her are over.
Her equally excellent combat reflexes, enhanced physical attributes, and forced improvement in intelligence are all results of Kaidou's "training."
Yamato has learned most of Kaidou's skills, and she's become increasingly adept at utilizing her own abilities, which means that when Kaidou fights her now, he has to be serious each time.
Sometimes it can take half a day, or even two to three days, with each bout being more intense than the last.
Although she doesn't feel fear, Kaidou is definitely the most troublesome opponent for Yamato.
Similarly, even fearless Luffy has his own psychological shadow—Garp.
Garp threw Luffy into deep chasms, left him alone in dangerous forests, and tied him to a balloon to float into the sky.
These were all things Garp did to train him into a strong Navy Soldier; combined with the Haki-filled Iron Fist of Love, Garp provided Luffy with a solid foundation, though Luffy's development was entirely different from what he predicted.
Heracles' comparison made him see reality directly and brought to mind some unpleasant images.
"Grandpa? Is your grandpa someone really strong?"
Besides Luffy, Nami also had some understanding of Heracross' language and heard the word "grandpa" from Heracles' tone.
"Ah, my grandpa is also a monster, but even so, not even my grandpa can stop me from becoming Pirate King!"
Luffy quickly emerged from his fear; this little thing wouldn't make him back down.
"Alright, Nami, keep steering; we're about to enter the Grand Line, right?"
"Should be. If Clown Buggy's nautical chart isn't wrong, the entrance to Inverted Mountain is just ahead."
Despite their fears, no one on the ship stopped moving forward. After regrouping, they continued their journey. Those monsters were terrifyingly strong, but based on the information they currently had, they didn't necessarily have to fight them.
"Alright, Usopp, stop being afraid over there. Didn't you want to become a brave Sea Warrior? Being scared like this won't do."
"Who's... who's scared? I'm not scared; I just wanted to look at my picture book, really. I just wanted to see my picture book."
Picking up the newspaper again, Usopp intended to change his mood, but the news on the paper once again caught his attention.
[Mysterious meeting between Hundred Beasts Kaidou and Red Hair Shanks. The Sea might be destroyed by the two of them.]
Morgans' sensationalist tendencies acted up again, using this "Four Emperors' meeting" to create a buzz, and the term Hundred Beasts caught Usopp's attention.
If he remembered correctly, Ulti, Page One, Yamato, and others' bounties all mentioned this term, which means Hundred Beasts Kaidou must be their Captain.
"Four billion six hundred seventy million seven hundred thousand...."
His excitement hadn't even subsided before he saw something more terrifying. If this was the person Yamato was referring to as wanting to become Pirate King...
Usopp's eyes rolled back, and he fainted with foam at his mouth, triggering his body's self-protective mechanism as he thought of indescribably terrifying things.
After the crew's hasty treatment, Usopp woke up by the time they had reached the vicinity of Inverted Mountain. The ocean currents had begun to surge, and looking into the distance, the reverse-flowing sea rushed up the peak of Inverted Mountain along the channel.
But besides Inverted Mountain, they also witnessed another spectacle: the entire sea was covered in red, and even the path to Inverted Mountain had a red hue.
This wasn't blood, but the color of Magikarp's scale armor.
At this time, it happened to be the pilgrimage season for Four Seas' Magikarp clans.
During this time, the weaker Magikarp would remain in their original habitats, while the stronger Magikarp would either follow their clan to cross over Inverted Mountain or head to Wano Kuni by traversing the Windless Zone.
For Magikarp living in the West or North Sea, returning to Wano Kuni was relatively easy, while for those in the South or East Sea, it was more challenging. Before evolving, Magikarp couldn't fly; they were just ordinary and weak fish.
This remains a puzzle that some scholars haven't figured out. They don't understand why these peculiar fish would migrate en masse at this time and then return to their habitats afterward, so they categorize it as fish migration.
It's also a human habit; people tend to use their known logic to explain new discoveries.
Magikarp have a strong reproductive capacity, and no one knows how many generations have spawned in The Sea now.
The pilgrimage journey has gradually become part of the trial journey for their clan, where some weak individuals are eliminated, while the strong ones evolve.
Each time this period comes, Inverted Mountain's passage is temporarily occupied by them, which even made the Merry halt for a while.
"The road's blocked, what do we do?"
"Don't worry. This situation lasts only two days at most, and soon it'll... Fool! Stop!"
Sanji, due to the Gyarados at Baratie, knew something about the situation here. Within two days, the Magikarp would pass through this route, but before he finished speaking, he saw Luffy trying to drive away the fish in another way, and he immediately kicked him away.
"What are you doing, Sanji! If we don't drive them away, how can we get through?"
"Listen carefully, if you really act, then we won't be able to get through at all!"
Boom! Boom!
Two cannons fell into the Magikarp school; lots of Magikarp were knocked unconscious by the shock of the explosion, and the source of the shells happened to be another pirate ship.
"Well, you'll find out what's going to happen soon...."
Looking at the unknown pirate ship, Sanji already regarded them as dead in his heart.
...
"Keep going! Some stinking fish think they can block my way? I must get my hands on the legendary Grand Treasure!"
On the pirate ship, a captain was giving orders. They didn't notice the terrifying red shadow that had appeared beneath the ship.
In the next moment, the red shadow suddenly rose and collided with the pirate ship.
That wasn't an evolved Gyarados, but a school of Magikarp. In this dangerous sea, the Magikarp had undergone certain changes.
It's still rare for Magikarp to evolve into Gyarados; some clans still exist without Gyarados protection.
To survive in these perilous seas, they eventually evolved to live in a way similar to Wishiwashi, forming their own unique "shoal."