"That's the gist of it. To sum it up: Armament Haki can strengthen your body and coat your weapons. At advanced levels, it can even strike the true bodies of Logia-type Devil Fruit users."
Earlier, after Cain stalled Captain Smoker, he spent some time explaining the nature of Logia fruits to the crew.
Now, the Straw Hats sat in a circle on the deck, listening intently as he continued his lecture.
"Next is Observation Haki. Zoro, try slashing at me from behind. Aside from Luffy, you and Sanji are the ones who absolutely need to master these two types of Haki first."
"I don't really get what you're trying to prove, but since you asked..."
Zoro stood up and walked behind Cain, who was sitting cross-legged on the wooden deck.
Just as the swordsman reached for his hilt, Sanji suddenly kicked him aside.
"OUT OF THE WAY, MOSS-HEAD!"
Sanji was not about to let a free chance to attack Cain slip by!
Irritated but curious to see what the chef could do, Zoro simply crossed his arms and watched from the sidelines.
"SHOULDER MEAT!"
Sanji lifted his leg high, spun like a top, and drove a vicious kick straight at Cain's shoulder.
"HE BLOCKED IT?!" Nami and Usopp shrieked in shock.
Cain didn't even turned around.
He merely raised a single pinky finger. As though he had perfectly predicted the exact angle and speed of the kick, he stopped Sanji's attack with no effort.
"Too slow! And your strength isn't anywhere near enough. Is this really all you've got?" Cain taunted him lightly.
Then, he yawned, closed his eyes, and casually lay down on his side next to Nami, his head resting only a few centimeters from her thigh.
That lazy taunt, combined with such a shameless flirtatious move, instantly set Sanji off!
Just as Cain intended.
Flames practically ignited in Sanji's eyes. He lifted his foot and stomped down viciously at Cain's skull.
In the blink of an eye—the spot where Cain had been lying was empty.
Now, he was leisurely sprawled out behind Luffy instead.
The provocation only grew worse.
Sanji's anger flared into an absolute inferno. He began stomping furiously, chasing Cain back and forth across the deck, only for every single lethal strike to be avoided with ridiculous, agonizing ease.
The whole time, Cain kept his eyes closed, toying with Sanji and weaving around everyone on the ship like a ghost.
"Huff... huff... What the hell are you doing?! Why can't I land a single hit on you?!" Sanji demanded between heavy breaths.
By now, he understood why Cain had deliberately asked to be attacked, and his burning anger finally cooled into realization.
Off to the side, Zoro looked secretly relieved.
If Sanji hadn't stepped in earlier, the one humiliating himself in front of the crew right now would have been him!
Only then did Cain slowly rise from the deck, brushing off his white suit.
He explained in a serious tone. "This is Observation Haki. By sharpening your inner senses, it lets you perceive everything happening around you, predict danger before it strikes, and make your body react automatically. Some people can develop it into unique sensory abilities, and absolute masters can even glimpse seconds into the future."
"What I just showed you was only the most basic form of Observation Haki, and even then, you couldn't touch me once. Let me put it clearly." He paused, looking at the monster trio. "Even if Luffy, Zoro, and Sanji all attacked me at the exact same time right now, you wouldn't be able to hurt me in the slightest."
Of course, even if he stood perfectly still and let the three of them hit him, their current strength wouldn't be enough to break through his dragon scales anyway.
Cain didn't say that part out loud. Instead, he moved on.
"The final kind is Conqueror's Haki. This isn't something you can gain through rigorous training. It is a terrifying disposition possessed by only one person in a million. At its core, it's an innate quality. Without the bearing of a supreme king, you cannot possess this power, let alone control it."
Everyone on the ship was stunned by the sheer rarity.
One in a million. The qualification of a king.
Just hearing the description carried an overwhelming weight.
"As for the deeper applications of Conqueror's Haki... sorry, but with your current strength, you aren't qualified to know about them yet. Telling you now would only give you unnecessary anxiety.... Alright, class dismissed!"
Cain waved his hand, signaling everyone to disperse.
But Luffy only half-understood any of the lecture. All that talk about kings and qualifications meant nothing to him, he just wanted to know how to get the cool invisible power!
He stretched his rubber arms out, wrapping around Cain like an octopus, refusing to let him go.
Cain sighed helplessly. "Luffy, you want to become the Pirate King, right? That refusal to lose. That stubbornness carved into your bones. That will to never fall, no matter how strong the enemy is. Because you have that unbreakable resolve... the seed of Conqueror's Haki has already taken root in your heart."
"YAY! THEN I CAN HAVE CONQUEROR'S HAKI TOO!" Luffy shouted excitedly, dancing around the deck before finally letting go of his brother.
Cain then turned to look at Zoro. Noticing the gaze, Zoro paused, clearly wondering what this had to do with him.
"Zoro, your dream is to become the World's Greatest Swordsman, right? I heard from Luffy where your massive chest scar came from." Cain smiled. "Even when facing a monster like Dracule Mihawk, you still had the courage to raise your swords and vow to surpass him. You have that qualification too."
Hearing those two grand examples, Usopp suddenly thrust a fist into the air.
"HAHAHA! IF THAT'S ALL IT TAKES, THEN I DEFINITELY HAVE THAT QUALIFICATION TOO!"
Bathed in the sunlight, the sniper actually gave off a brief inexplicable aura of gigachad.
But Cain crushed it with a single sentence.
"No, no. That's not the bearing of a king. That's just you loving to brag."
As Cain turned his head, he saw Sanji sidling over with an ingratiating, hopeful look on his face.
For a moment, Cain genuinely didn't know what to say.
In the original timeline, it was never explicitly confirmed whether Sanji possessed the disposition of a Conqueror or not.
Cain swallowed hard before speaking with extreme difficulty. "Sanji... sorry, but... I honestly can't tell whether you have that kind of qualification or not."
Zoro stepped up, slapping a heavy hand on Sanji's shoulder to mock him.
"Don't feel bad man relax.... You're just a cook, after all."
"Sanji, I'm hungry," Luffy chimed in immediately.
Those two short sentences left Sanji frozen in place, turning him into a petrified gray stone statue of despair.
"I've said enough for now. I'll explain more battle techniques later, Sanji, don't get too down. If it's meant to be yours, it will awaken eventually. Here, take this for now. Consider it temporary compensation."
Cain tossed Sanji a small, leather-bound booklet.
It was the manual for Geppo, the Sky Walk technique from the Marine Rokushiki. Though it was a classified Marine art, it could be learned through personal understanding, and plenty of powerful pirates used similar moves.
Besides, Sanji was destined to learn the technique eventually anyway—though originally, it involved running for his life from an island of Okama first!
"Oh? The timing is perfect." Cain looked up at the sky as heavy rain began falling again.
By now, the Going Merry had finally drifted out of the Calm Belt and returned to the turbulent waters of the standard sea route.
While explaining Haki earlier, Cain had quietly summoned his flame clouds beneath the hull, subtly pushing the ship out of the monster-infested waters.
But as the rain fell, Cain felt like something was missing.
Scratching his head, he looked around the deck. His eyes landed on a wooden barrel, and he suddenly remembered.
Between Luffy's run-in with Dragon, the clash with Smoker, and fleeing the Calm Belt, the chaotic rhythm of the day threw them off.
They had completely forgotten the iconic departure ceremony!
As it happened, Sanji—having regained his spirits after reading the manual—thought of it too. He immediately carried the heavy barrel into the center of the deck and grinned at the crew.
"To celebrate the ship entering the Grand Line... let's hold a departure ceremony!"
"YEAH!"
"LET'S DO IT!" Everyone cheered at once.
Sanji placed his foot on the barrel first, declaring firmly, "I'm going to find the All Blue!"
Then came Luffy, grinning with his signature, unbreakable resolve. "I'm going to become the Pirate King!"
Next, Zoro stepped up, his tone calm and steady. "I'm going to become the World's Greatest Swordsman!"
Nami followed, her eyes shining bright. "I'm gonna draw a map of the entire world!"
Usopp hesitated for a second, but gathered his courage, slammed his foot onto the barrel, and shouted, "I'm going to become a brave warrior of the sea!"
Once everyone declared their grand dreams, all eyes turned to Cain.
Cain stepped forward, slowly placed his foot on the barrel, and spoke softly.
"I just want to live a peaceful life."
That simple sentence stunned everyone.
No one disliked it, but they truly didn't know what to make of it.
The most confused of all was Sanji.
Cain just explained that grand, world-shaking ambitions were the very foundation of Conqueror's Haki.
So what kind of terrifying ambition would a monster like Cain hide behind those words?
Yet it turned out to be something so... ordinary.
Seeing their blank expressions, Cain smiled and explained.
"In this world as it is now, war is constantly breaking out. Pirates run wild, burning, killing, and looting wherever they please. For ordinary people, living peacefully is incredibly difficult. What I want to do... is change this entire world. I will forge a place with my own two hands where I can finally live that peaceful life."
Only then did the crew understand the weight of his dream.
"TO THE GRAND LINE!" Luffy shouted, shattering the barrel with a final cheer.
The crew rushed to their stations, taking control of the Going Merry as it slowly approached the roaring currents of Reverse Mountain.
"So that's Reverse Mountain? Up close, it really is incredible!" Luffy chewed on a massive chunk of meat, staring up at the towering red cliffs in sheer amazement.
"EVERYBODY HOLD TIGHT! LOWER THE SAILS, GRAB THE HELM, AND DON'T LET THE MERRY CRASH INTO THE ROCKS!" Nami hurriedly issued orders over the roaring rapids.
Everyone sprang into action.
Cain hadn't forgotten that this was the exact moment the ship's rudder was originally supposed to snap.
Sure enough, as Sanji and Usopp started panicking and bickering over the wheel, Cain kicked them both aside.
He grabbed the helm with one hand, flared his Observation Haki to precisely predict the chaotic currents, and wrenched the ship violently into position.
The Going Merry hit the raging rapids flawlessly, entering the correct waterway without a single scratch, and began its impossible, roaring ascent up the sheer cliffs of Reverse Mountain.