Garp and Sengoku had only just finished seeing off the prisoner transports when Cain and Uta arrived from the sky.
Dark clouds churned overhead as Cain's enormous dragon body coiled through them, looking almost exactly like Kaido used to whenever he casually flew around Wano in Azure Dragon form.
Sengoku looked up at the massive shadow covering half the harbor and immediately started complaining.
"Is this brat serious? He beats Kaido once and suddenly thinks he needs to make an entrance like this? What's with flying over here as a giant dragon?"
Garp's eyes, on the other hand, lit up.
"Perfect! I could use the practice!"
Sometimes Garp had to admit that when it came to beating up his grandson, the experience overlapped almost perfectly with beating up pirates.
And these days, the words Cain and pirate had become nearly interchangeable anyway.
Seeing such a huge target circling overhead immediately made his fists itch.
Besides, Uta was sitting on Bella farther away, so there was no risk of accidentally catching her in the crossfire.
"Let Grandpa see just how much stronger you've gotten!"
"Hey, is that really how a grandfather is supposed to behave?"
Sengoku objected verbally, but his feet didn't move an inch.
"How would I know unless I test him?" Garp shot back. "That brat just defeated Kaido. And weren't you the one yelling earlier about wanting to beat him up too? You're his teacher. Don't you want to know how strong your student is now?"
"…Damn it. When you put it like that, now I kind of do."
The two old men fell into perfect sync, almost like the old days when they had fought Golden Lion Shiki together.
Both hooked their fingers under their collars, instinctively preparing to fling aside the Justice coats hanging from their shoulders—
and froze.
They weren't wearing Justice coats.
They were wearing kimono.
The moment they pulled, both robes slipped straight off their shoulders and started flapping wildly in the sea breeze.
Cold wind rushed over their bare chests.
Within seconds, Garp and Sengoku were standing half-naked at the edge of the harbor, with little more than their underwear left keeping what remained of their dignity intact.
Both old men turned bright red and started frantically grabbing for their clothes.
High above, Cain's dragon eyes widened.
"These two seriously prepared this kind of surprise for me the moment I arrived?"
He stared in disbelief.
"Did they develop some weird new hobby while I was gone?"
Fortunately, Cain had activated Observation Haki before arriving and seen the disaster coming, so he had already lowered his tail in front of Uta and Bella to block their view.
What Cain didn't realize was that, in the minds of the thoroughly humiliated Garp and Sengoku, an enormous invisible symbol reading DANGER had just appeared over his head.
…
"So… Cain, what exactly happened just now?"
Uta kept pressing him for an answer.
Bella leaned in as well.
"Yeah! Bella wants to know too. Why does Papa look like this now?"
Cain's entire face had swollen until he looked like a pig.
Garp and Sengoku stood on either side of him, each gripping one shoulder firmly.
"Nothing happened just now."
Sengoku's face was perfectly expressionless.
"Right?"
Garp smiled with terrifying grandfatherly warmth.
"You didn't see anything."
"Right?"
"R-Ryep…"
Cain forced the answer through swollen lips.
Bella tilted her head.
"Papa, what did you say? Bella couldn't hear."
"N-Nothing."
Cain immediately changed the subject.
"So, about imprisoning Kaido…"
Sengoku listened as Cain explained and nodded.
"Garp and I were discussing the same problem earlier."
His expression grew more serious.
"But Kaido is still sitting at the bottom of the sea. How exactly are we supposed to retrieve him?"
"That part's easy."
Cain clapped his hands with complete confidence.
"Kaido passed the title of Strongest Creature on Land, Sea, and Air to me."
"If I'm going to carry a title like that, I should at least be able to live up to it."
He grinned.
"If anything, fighting in the ocean gives me an advantage."
Both old men stared at him with identical expressions that clearly asked whether he was being serious.
"You'll understand when we get there."
Cain didn't explain further and simply led everyone away from the harbor.
…
Much of the sea around Onigashima was still frozen.
The ruined island itself remained in roughly its original position, though cracks and burn marks covered nearly every surface, making it completely uninhabitable for the time being.
As for how long recovery would take, nobody could say.
That was something only time could fix.
Cain walked to the edge of the water and, under the stunned gazes of Garp and Sengoku, stepped straight off.
Yet when he descended, his feet never actually touched the sea.
A powerful current of wind formed beneath him the instant he dropped, supporting his body comfortably above the surface.
Clearly, Cain no longer needed to enter hybrid form to access the techniques of his Devil Fruit.
Then enormous masses of Flame Clouds emerged around him.
The clouds pressed against the surrounding seawater with tremendous buoyant force, forcing the ocean apart and creating a gigantic whirlpool.
The water rotated violently as it was pushed aside, and within only a few breaths, a transparent passage leading all the way to the floor of Wano's inland sea had formed.
Flame Clouds churned along the walls of the tunnel, suspending Cain in midair the entire time.
He looked absurdly comfortable.
Garp's eyes immediately lit up.
Without hesitation, he jumped inside.
The buoyancy caught him at once, leaving his body floating weightlessly in the tunnel.
After enjoying the sensation for a moment, Garp looked upward and shouted enthusiastically,
"Sengoku! Uta! Bella! Come down here! This is actually really comfortable!"
Then he casually reached over and ruffled Cain's hair.
"Not bad, brat."
"You've taken your ability this far already. At this rate, there really won't be many people left in the world who can do anything to you."
Uta and Bella quickly jumped in as well.
Strictly speaking, neither actually needed the tunnel. Uta could use Uta World to isolate herself from the seawater, while Bella could simply freeze a path through it.
But both clearly wanted to experience Cain's new trick.
Sengoku was the only one who didn't jump immediately.
He stood at the edge of the whirlpool and stared down into the tunnel Cain had carved through the sea.
A different thought was running through his head.
'Does Cain's bounty need to go up again?'
Judging by this level of power, he was probably going to have a serious conversation with Sakazuki once they returned.
Then another thought occurred to him.
Where exactly was the Admiral Sakazuki had dispatched?
It had already been several days.
Sengoku hadn't agreed with Sakazuki's decision in the first place, but once an order was given, an Admiral disappearing without a trace was still unacceptable.
'When I get back, I should ask whether that man's salary needs to be docked.'
…
Once everyone reached the seabed, they were all stunned by what they found.
"There's… a palace down here?"
Sengoku stared up at the ruined yet imposing architecture in disbelief.
"It's more than just a palace."
Garp slowly scanned the area, unusually serious.
"There's an entire city."
He frowned.
"Judging by the scale, this might be the Wano of some ancient era."
Cain said nothing.
He knew perfectly well what lay buried beneath these ruins.
Pluton.
He had no particular interest in the Ancient Weapon itself, but there was absolutely no chance he wanted these two high-ranking Marines discovering it.
Whether Sengoku could keep the secret was one thing.
His own grandfather's mouth alone was dangerous enough to punch a hole through the sky.
If Cipher Pol ever learned what was hidden beneath Wano, the country's situation would become far more dangerous overnight.
So Cain immediately flew deeper into the ruins and deliberately redirected everyone's attention.
"This isn't the time to study ancient buildings."
"Let's find Kaido first."
They followed the enormous crater Kaido had created during his fall and eventually reached the bottom.
Kaido was lying across shattered ice, breathing evenly while his snores thundered through the ruins.
He still hadn't woken up.
"How is he still asleep?"
Garp crouched and poked Kaido's cheek.
Then he looked back at Cain.
"You've already woken up. His injuries weren't that much worse than yours, were they?"
Sengoku frowned.
"Cain… are you actually that much stronger than him now?"
"Come on, that isn't a fair comparison."
Cain spread his hands.
"I've spent the past few days eating properly and being looked after."
"Kaido, meanwhile, has been lying alone at the bottom of the sea this whole time."
Cain glanced down at him.
"When you put it that way, it's actually kind of pathetic."
Then he answered more seriously.
"But purely in terms of physical toughness, yeah, I'm probably a little harder to put down than Kaido."
"And if you count Bella too, I could probably overwhelm him pretty easily."
The moment those words left his mouth—
Garp grabbed Cain by the head.
His fist cracked ominously.
"So let me get this straight."
"You could've crushed him if you used everything available to you, but instead you spent two days and two nights beating each other half to death just so the rest of us could worry ourselves sick?"
Cain clutched his head.
"I just wanted a proper one-on-one fight with Kaido!"
"Using Bella's power would've been unfair."
"Unfair?!"
Garp punched him straight on top of the head.
His shout echoed throughout the underwater ruins.
"A fight is a fight!"
"You're pirates! Since when do pirates care about fairness?!"
"Linlin fights with her Homies all the time!"
"What exactly were you even worried about?!"
Cain went silent.
Then slowly blinked.
"…Oh."
Another pause.
"…Yeah, actually."