"East Blue? That's outside the New World—no, outside the Grand Line?" Yamato grew even more interested. "Can you tell me what the outside world is like?"
She'd grown up in Wano and Onigashima, and since she started calling herself Kozuki Oden, her father had confined her, so she'd never been to sea. She longed for the outside world.
More importantly, her idol Oden had craved freedom and adventure, so she felt she should too.
"Well, that's a long story."
Gusion sensed a power watching this place, so he stayed cautious.
Yamato wasn't a bad person—just a hardcore fangirl whose idol was problematic. Still, he had his own ideas for the Devil Fruit quest.
Besides, killing the Oni Princess of the Beasts Pirates in Wano was just asking to die.
"That's fine! We can't go anywhere anyway, so tell me about the outside!" Yamato's eyes sparkled—she loved long stories.
Since he wasn't planning to attack his cellmate, Gusion changed his mindset. "I can tell you about the outside world, but you have to agree to one thing."
"What is it? Please say it! I, Kozuki Oden, always keep my word!" Yamato urged.
"I'm very interested in how this country uses Haki. Can you teach me?" Gusion had a new idea after meeting Yamato. He didn't need to go find Old Man Hyogoro—Yamato was the perfect teacher: Kaido's daughter, skilled in all three Haki, and easy to fool.
Plus, she might have inherited Kaido's excellent teaching ability.
"Haki? Of course! I was going to teach you anyway. You look a little weak, and you're my comrade in overthrowing Kaido! Leave it to me!" Yamato slapped her chest, making her chest tremble a bit.
She agreed so readily that Gusion was stunned. He didn't expect to get such a bonus from being imprisoned.
"…Did you just call me weak? Never mind, I'll tell you about the outside. Where shall I start?"
"Anything! I'm interested in all adventures outside! I yearn for freedom!"
Yamato was thrilled. She hadn't expected to meet a kindred spirit in prison, and from the outside world too.
Gusion started telling her about the strange islands, nations, and customs he'd seen. He wasn't much of a storyteller, but Yamato was enthralled—she had few friends in Wano and lived a lonely life.
Since they had a deal, Gusion wasn't in a rush to study Haki. He'd win Yamato over first, then get her to teach him seriously.
They chatted all night. By dawn, Yamato was still fired up. "Wow, there are even islands in the sky? The outside world is amazing! I want to see it!"
"Didn't you say you wanted to open Wano's borders? Why do you always want to go out?" Gusion asked.
Yamato didn't notice the contradiction. "Because I'm Kozuki Oden! I yearn for freedom, so of course I want to adventure! But because I'm Oden, I also have to open Wano's borders and defeat Kaido."
Gusion was exasperated by Yamato's brain circuits. Of all people to idolize, she chose Oden—someone both wanting to open the country and run off adventuring at a time of crisis.
But after talking up close, he felt that maybe, because of her age, Yamato wasn't yet so brainwashed. She genuinely longed for freedom, not just under Oden's influence.
But Yamato herself didn't realize this. She called herself Oden, cut ties with Kaido, and never admitted being his daughter.
"I talked all night—my throat's dry. Let's continue tonight. I want to train my Haki now," Gusion ended the story session.
"Time flies! This is the first time in eight years I've talked with someone my age for so long." Yamato's joy was obvious. "Since you're tired, it's my turn to teach."
Once she entered teaching mode, Yamato became surprisingly serious. "Gusion-dono, show me your Haki first."
Gusion activated his passive Armament Haki, covering his arm and making it visible.
Previously, to avoid standing out, he had his Haki passively concealed, so Yamato hadn't noticed his level.
"Not bad! What you lack is just advanced technique." Yamato praised. "Now, you need to project your Haki outward, forming a buffer like air around your body."
She demonstrated, coating her hand with Armament Haki, using the Ryuo technique. A cherry blossom-like aura coiled around her hand.
She reached out, and even from a distance, Gusion's fist was pressed back by her force.
"That's Ryuo…"
Seeing Yamato's Haki up close, Gusion realized the difference—a qualitative change from ordinary Armament Haki.
Yamato's movement was slow and clear, letting Gusion sense the subtlety of the technique. He quickly understood why he'd failed before.
"Can we spar? Let me try," Gusion suggested, standing up.
"No problem, but be careful—I'm pretty strong," Yamato warned.
Gusion nodded. Yamato didn't hesitate, throwing a punch.
With his hands shackled, Gusion could only use both fists to meet her.
As their Haki collided, Gusion was sent flying, cracking the wall behind him.
He stood up, delighted. Ryuo and ordinary Armament Haki were truly worlds apart.
Because of the Seastone, Yamato wasn't stronger than him, but her Ryuo sent him flying—that was its power.
In short, ordinary Armament Haki just made attacks harder; for real power, you needed great strength and speed.
Old Man Hyogoro, for example, was too weak to hurt anyone here with regular Haki. But with Ryuo, he could even knock out wardens.
Luffy, too—his stats couldn't compare to Kaido's, so normal Haki was useless. With Ryuo, he could finally hurt Kaido.
To sum up, Ryuo was a huge power boost, both offense and defense; a qualitative leap in Armament Haki.
"You okay?" Yamato asked, seeing Gusion grinning after being sent flying.
"I'm fine. Let's go again—I think I'm getting it!" Gusion realized it was better to practice physically with Yamato than listen to her theory. With her careful guidance, he could quickly grasp the knack.
Bang! Bang! Bang!—
The cell echoed with the sound of bodies hitting the wall, annoying the neighbors so much they cursed: "Are you two maniacs? If you have so much energy, go dig!"
Gusion and Yamato ignored the complaints, absorbed in their Haki training.
Since both still had injuries, the wardens didn't call them out to work. If only Gusion was lively, they'd have made him dig. But since it looked like Yamato was beating up Gusion, they figured she was venting her anger, so nobody dared interfere.
They even felt sympathy for Gusion and decided not to make him work for a few days.
Gusion didn't know what the wardens were thinking, but he was happy to keep training with Yamato.
Boom—
Finally, during one spar, Gusion sent Yamato flying, nearly smashing through the reinforced wall.
Looking at the translucent, dark-red Haki wrapping his fist, Gusion grinned and helped Yamato up. "Thanks. I've mastered Ryuo."
After a day's practice, he could now use Ryuo reliably.
Since his Haki was listed under Origin Seed, he could control its output, switching between ordinary Haki for daily life and Ryuo in battle.