Kai glanced at the group and slowly said, "Armament Haki is related to mental will, but more importantly, it's about the body's strength.
The body's strength and mental will determine the power of Armament Haki.
As for you three, after cultivating the Body Forging Method, your bodies have already met the standard.
Next, practice Armament Haki according to the methods in the Armament Haki book."
"However, I must warn you. Once you finish cultivating the Body Forging Method, I will personally train you with this fist, covered in Armament Haki."
"Wh-What?!" Luffy jumped up, clutching his head, a look of despair on his face. "You're going to hit us with that fist?!"
Zoro frowned slightly, his mouth twitching. "You're really ruthless."
Sanji's expression stiffened, and there was a hint of dissatisfaction in his tone. "Kai, isn't this using public office for private revenge?"
Kai sneered, slowly raising his right fist, the black Armament Haki once again covering it:
"This isn't private revenge; this is your training.
If you want to master Armament Haki, you must withstand my attacks.
During this process, you will suffer, you will want to give up, but if you don't persevere, then you'll never step into the realm of the strong."
As he spoke, he lightly swung his fist, and the force of the punch carried a heavy sense of oppression, directly splitting a wooden pillar on the deck.
Wood splinters flew, and everyone couldn't help but take a step back.
"Don't say I didn't warn you." Kai's gaze swept over the three, his tone low,
"You must be prepared and master the methods of cultivating Armament Haki. Until you learn it, I won't go easy on you!"
Luffy looked up and shouted, "Okay! No matter how difficult, I'll learn it! I want to be the Pirate King; how could I be defeated by these difficulties!"
Zoro gritted his teeth, his eyes firm, and said, "Me too. To become the world's greatest swordsman, this pain is nothing."
Sanji sighed, lit a cigarette, and a slight smile played on his lips. "Forget it, who told me I followed a bunch of lunatics? Kai, come on, we're ready."
Kai looked at them, a cold smile appearing on his lips. "Don't celebrate too early. Your training has just begun."
The sea was calm and waveless, sunlight spilled onto the deck, and the Going Merry sailed slowly in the gentle breeze.
However, the ship was in chaos.
"Bang!"
"Ah! Don't hit my face, Kai!"
"Ah ah ah! I can't take it anymore! If you hit me again, my nose will be crooked!"
On the deck, Luffy, Zoro, and Sanji, blindfolded, were undergoing Kai's "special training."
Kai stood before them, his fists covered in pitch-black Armament Haki, each punch landing squarely on the three of them.
"Luffy, you not only have to use Armament Haki to block my attacks now!"
"You also have to activate Observation Haki to anticipate my attacks!" Kai said coldly, his voice devoid of sympathy.
Luffy, though unable to see, instinctively raised his arm.
But with the seastone fragments on him, his movements were clearly a beat too slow, and Kai's fist landed directly on his shoulder.
"Ah ah ah! My shoulder is going to break!" Luffy wailed loudly, falling onto the deck, his whole body collapsing into a puddle of mud.
"Stop whining!" Kai looked at Luffy lying on the ground, his tone unfriendly. "If you can't endure this much pain, how can you become the Pirate King?"
"Don't say it so easily! It really hurts!" Luffy clutched his shoulder, his face full of grievances, but he still struggled to his feet and resumed his stance.
Zoro and Sanji weren't much better; although they were agile.
But facing Kai's fists covered in Armament Haki, and being blindfolded, they were beaten to tears.
"Hey, Kai! Hitting Luffy is enough, don't involve me!" Sanji shouted while dodging wildly, a bruise already forming on his face.
"Less talk! You're all the same; if you don't train your Observation and Armament Haki well, you're just asking for death!" Kai showed no mercy, throwing another punch at Sanji.
Zoro gritted his teeth, his brows furrowed, trying to activate Observation Haki to evade Kai's attacks.
But Kai's Armament Haki-covered fist struck his arm hard, forcing him back several steps.
"Tch... this guy is just looking for an excuse to beat us up, isn't he!" Zoro complained in a low voice.
On the other side of the deck, Nami and Usopp were exercising.
They were doing push-ups while secretly glancing at Kai and the trio's training, their expressions gradually twisting.
"Nami... do you think we'll also be beaten like that by him later?" Usopp's voice trembled, and cold sweat trickled down his nose.
Nami gritted her teeth; though she didn't want to admit it, she still nodded. "Probably... after all, Kai never goes easy."
"It's over..." Usopp collapsed onto the ground, looking desperate. "Will I even survive to the Grand Line?"
"Stop talking nonsense! Keep exercising!" Nami glared at him fiercely, but inwardly, she was already starting to fear for her own future.
Just as wails filled the deck, Kai suddenly stopped what he was doing and turned his gaze towards the sea.
His brows furrowed slightly, and his voice was low. "Wait, there's someone in the sea."
"In the sea?" Luffy, Zoro, and Sanji simultaneously pulled off their blindfolds, looking in the direction Kai was gazing.
Indeed, a figure was floating on the surface of the sea.
"Luffy, save her!" Sanji urged.
Upon hearing this, Luffy immediately stretched out his arm. "Gum-Gum Rocket!"
His arm flew out like a spring, accurately grabbing the person and pulling her back from the sea.
It was a girl who looked eleven or twelve years old, her face pale and her body drenched.
"It's a little girl." Sanji walked over, took off his jacket and draped it over her, his tone gentle. "Don't be afraid, you're safe now."
The girl slowly opened her eyes, and when she saw the people on the ship, her body trembled violently.
Her eyes widened, full of vigilance. "You... you're pirates?!"
"That's right, we're the Straw Hat Pirates." Luffy grinned.
"Ah!" The girl exclaimed, quickly backing away, looking utterly terrified. "Pirates! Don't come any closer!"
Nami quickly walked forward, waving her hand to comfort her. "Don't be scared, we won't hurt you."
"That's right, we just saved you." Usopp chimed in.
After hearing everyone's words, the girl's emotions calmed down a bit, and she cautiously asked, "You... you really won't hurt me?"
"Of course not." Kai walked forward, his voice calm. "However, I'm very curious, why are you out at sea?"
The girl lowered her head, looking a little flustered. "I... I escaped from a Marine ship; they're chasing me."
"Marines?" Luffy tilted his head, a puzzled expression on his face. "Why are the Marines chasing you?"
The girl bit her lip, silent and looking down.
"It's the Millennium Dragon, isn't it?" Kai said faintly.
"How did you know?!" The girl suddenly looked up, staring at Kai in shock. "How do you know about the Millennium Dragon?"
Kai's gaze was deep, his voice low. "I have the talent to foresee the past; some scenes from your past were captured by me."
Upon hearing this, everyone showed expressions of understanding; they had long known that Kai's foresight talent was an extremely rare form of Observation Haki.
"Because my Observation Haki has made some progress." Kai's tone was calm. "Even my ability to foresee the past has become much stronger."
The girl looked at Kai, her eyes full of awe. "You... you're amazing! Please, help me!"
The girl bit her lip, tears sparkling in her eyes. "Help Dragon-sama! It's about to die of old age.
I want to send it back to the Dragon's Den, which is Lost Island, but I don't know where it is..."
"Millennium Dragon? Dragon's Den? Lost Island?" Luffy's eyes instantly lit up when he heard these words. "That sounds so interesting! All right, we'll help you!"
"Really?" The girl was stunned for a moment, then her face lit up with joy. "Thank you! Thank you!"
Kai looked at the excited Luffy, a slight smile playing on his lips. "It seems we have a new adventure."