Gigantic Defeat  

The stony giant lacked the overwhelming power it possessed earlier. Simply put, this was likely due to the damage it had sustained from Junshi's devastating blow. Though they grappled, it could no longer overpower Feiyun.

He had no formal combat training, yet the ominous 'voices' he sensed guided him on where to anticipate attacks. With his injuries hindering his movements, this alone allowed him to evade the strikes.

Additionally, Kuro's 'Darkness' periodically spread across the ground, ensnaring the stony giant's feet and restraining it.

Unarmed and lacking proper weapons, even Feiyun could still subdue him under these circumstances.

"Hah...Hah...!"

"Damn...for me to be overpowered by a mere girl...!"

In their current pure contest of force, the advantage lay with Feiyun. Junshi's strike had truly taken its toll, yet...

"Dammit...! If it's come to this, I'll use any means necessary!!" The stony giant reshaped itself, coiling around Feiyun like a cage to prevent her escape.

The man, having vanished once more, burrowed into the earth - grasping his most formidable weapon made possible by his Rock-Rock Fruit's powers. By assimilating with stone, any rock could become a weapon or armor for the Ability user. While greatly influenced by the wielder's skill, this man proved a true genius in that regard.

Rumble!

The earth split in two...

"Oh...Ooooh!?"

As if the ground itself had opened its maw, the center caved inward to swallow Junshi, Kuro and the others while the stone on both sides closed in to crush them all. Had the sea not frozen over, seawater would have flooded in.

"Hey, hey, hey! What do we do about this, we'll die!" Hollered George.

"Kuro!" Junshi called for his assistance.

"Don't be stupid, my gravity powers can't handle something like this." 

"This is no time to stay calm!"

Junshi and Kuro considered any way to overcome the situation, ignoring the panicking George.

Yet facing the rapidly encroaching stone walls intent on crushing them, they had no recourse remaining.

Was there truly nothing they could do?

Sensing their resignation, the man sneered from within the earth.

However--

"--Freeze."

A succession of thick ice pillars formed a shield, halting the encroaching earth.

The stone reshaped into spears, raining down in an attempt to impale the descending Kanata. Yet the strikes lacking Armament Haki did no damage as her shattered body reconstituted itself.

Zen rode down atop the ice pillars that served as his foothold.

"Sorry I'm late." Kanata relayed to the others.

"Hihin, just in the nick of time." Zen looked towards Feiyun.

"No, I'm relieved...if it's not too much trouble, can you do something about that?" said Junshi.

Escaping was easy enough if she simply created an ice staircase. But that alone wouldn't defeat their foe. Both his durability in withstanding Junshi's Drilling Dragon Strike and the extent of his Ability's usage showed he certainly possessed the power to reign over this West Blue sea.

That was, if Kanata's group hadn't confronted him first. "Kuro, can you drag him out?" 

"Who knows. If he's underground, excess debris might get pulled along too." 

"Just give it a try. If we can drag him out, it'll be smooth sailing from there."

"I see. Got it."

In any case, failing to extract him eliminated any chance of victory. Only Observation Haki users like Kanata and Junshi could pinpoint his location.

With Feiyun trapped in the stony cage, immobilized, Zen moved to free her instead.

While gearing to release his powers, Kuro said, "I can't tell where the guy is though." 

"Over there." Kanata pointed ahead.

"All right, got it - Dark Water Vortex!"

Following Kanata's direction, Kuro aimed his powers to pull the Ability user's true form toward them.

Had the foe been wearing stone armor above ground, dragging just the 'core' without the surrounding material would be impossible. But hiding underground was another story entirely.

Crunch! Crunch! 

The shattering of earth rang out as a giant stone arm erupted, lashing out at Kuro in attack.

Sensing the pull dragging him forth, the foe struck preemptively from beneath the surface.

Yet this level of threat could be handled by Junshi alone.

"Hmph!!"

Shattering the flailing stone arm with his blows, the Ability user finally revealed himself as he fled to the surface. 

Perhaps having learned from their earlier clash, he emerged encased in stone armor of a manageable size. Unable to escape, he likely intended to defeat them directly.

"Dammit! I'm gonna freaking kill you all!!"

Screaming in fury, the stone arms lashed out at Junshi with Kuro's gravity enhancing their momentum.

Boom!

Junshi caught the blows, using their force to hurl the man skyward in a judo-like throw.

Seizing that fleeting moment, Kanata brought her powers to bear.

"Kanata!"

"Leave it to me!"

She froze over the caved-in earth's surface, and Junshi flung the man onto the ice.

The Rock-Rock Fruit allowed manipulation of stone through physical contact... Separating the two nullified its effects.

They had him cornered now. Though the skirmish dragged on, with him driven into this predicament, ending it became trivial. Defeating the man before them would resolve everything.

"Hah...Hah...Don't think...you've got me cornered...with just this much...! I'm not...finished yet!!"

Coughing up blood, the man defiantly resisted as his stone armor reshaped, spiked soles crashing down in hopes of shattering the thick ice. 

Yet such strikes could never breach Kanata and Junshi's guard.

"No, it's over."

In the blink of an eye, Kanata froze the man's entire body in ice, following this, she hardened an ice spear for Junshi which he fashioned with Armament Haki before piercing the enemy's heart.

Blood dripped from the spear protruding through his back as the ominous 'voice' he sensed through Observation Haki faded away.

Inhaling the blood-tinged air, they felt the battle's conclusion.

"...So we finally defeated him." Kuro was relieved.

"Oh man...I really thought I was done for."

The exhausted Kuro collapsed while George continued sobbing. They never imagined facing such formidable foes, their foresight proving lacking.

While further reinforcements would prove troublesome if present, this man launching an offensive likely ensured his subordinates met the same fate. Any remnants lingered at sea, yet those ships had already been sunk - what more could they accomplish on the frozen waters?

As Kanata considered returning to the harbor, a voice called out from above.

"U-Um, are you all right?" Feiyun timidly peeked over the pit's edge. The stony prison confining her seemed shattered by Zen, leaving only minor scrapes but no major injuries.

"Feiyun, sorry but could you pull us up?" 

"Of course, happy to help."

Leaping down, the already shrunken Feiyun discovered the pit's depth exceeded even her current giant size.

Increasing her frame slightly, she cupped them in her palm to carry back to the surface.

Between Junshi's rampaging and Feiyun's clash with the stony giant, the harbor lay utterly devastated from their battle.

Chinjao would undoubtedly chastise them severely later.

"You've been through quite the ordeal." Feiyun said to Kanata wo responed: 

"Indeed, fighting this caliber of foe proved a novel experience for me as well."

Lacking mastery over Haki, the man could never defeat Kanata directly... Yet his Ability alone rendered overpowering him conventionally impossible without finding his true form through Observation Haki first.

In any case, with the threat resolved, they had to handle the aftermath.

"With this level of destruction, he's bound to have noticed. Best to contact Chinjao. If money is needed, offer up that Devil Fruit from the ship."

"You're giving that away, Kanata? It was quite the find though," Junshi murmured.

"After causing this much devastation, he'll likely demand compensation from us as well. I'd rather not hang myself over just the payment fees."

In which case, transitioning to piracy may become their only recourse. While ignoring the debt would turn Chinjao's forces against them, they had no intention of going down so easily. But avoiding needless conflict proved preferable if possible.

Kanata fundamentally espoused pacifism and valued order after all. Yet she also harbored an insatiable greed for greater strength.

"Still, it depends on how much that Devil Fruit can fetch."

According to Kanata's knowledge, the market price was said to be around 100 million berries, but would that cover the excessive damages?

Gazing upon the frozen Ability user's corpse in the caved-in harbor, a thought crossed her mind.

"...Hmm."

After returning to the ship briefly, she brought Kuro back down into the pit. Retrieving a spare fruit, she approached the heart-pierced man.

"...What are you doing?" Kuro inquired with a sense of bewilderment.

"You see, when an Ability user dies, the same Devil Fruit will eventually reappear somewhere in the world."

So why did such 'reincarnation' conditions arise?

In keeping with their demonic name, Kanata theorized that consuming a Devil Fruit allowed the eater's body to house an actual devil. Upon death, the devil would abandon the deceased vessel, reappearing as a reborn fruit somewhere for another to consume. The reason behind this phenomenon remained uncertain, but Kanata realized she could exploit it nonetheless.

"It is said that eating a Devil Fruit allows one to house a devil within their body. Consuming two would cause the body to burst from being unable to contain them both. So when they die...where does the devil go?"

"You think it inhabits that fruit instead?" 

"A possibility. I brought you along as part of an experiment as well."

Kuro's Yami Yami no Mi granted the power of 'Gravity'. As demonstrated in dragging the Ability user's true form during battle, if that gravitational pull could attract the escaping devil after death--

Then it provided ample justification for 'Ability User Hunting'.

Alternatively, if the devil simply inhabited the nearest available fruit, gravitational forces may prove unnecessary altogether.

Bringing the fruit in her left hand closer to the fallen man's chest, she waited briefly.

Then--

"Oh...Ohhh?" 

"...Hmm."

Strange markings gradually surfaced on what had been an ordinary fruit moments prior.

Unmistakably--the characteristic patterns unique to a Devil Fruit.

A small smile graced Kanata's lips as she pocketed the fruit.

"The experiment was a success." 

"So defeating a Devil Fruit user allows you to obtain their Ability, huh?" 

"At least immediately after their demise, it would seem, Kuro."

While hypothetical, the premise now had corroborating evidence. Powerful Abilities could be bestowed upon allies, while undesirable ones could simply be sold for profit.

It provided justification for prioritizing Ability users as targets.

"But if word of this gets out, wouldn't that be bad?"

"Indeed. The more formidable the Ability, the more it would be hunted. Best you remained vigilant as well."  She warned him.

"I pride myself on being the weakest Ability user around."

"You say that yourself. At minimum, your powers have uses, not the kind anyone would bother stealing. Let's hope the transference conditions remain unresolved."

Eventually someone may discover this and pursue 'Ability User Hunting', but as far as Kanata knew, only the future 'Blackbeard' decades from now potentially grasped the transference mechanics. 

How he learned of it remained a mystery...but this knowledge could prove advantageous nonetheless.

Combined with the Yami Yami no Mi's 'Ability User Killing' properties, systematically acquiring Devil Fruits may represent the optimal approach.

"For now, just you and I need to know. The fewer who are aware, the better."

"Yeah, yeah, be sure to protect me then." 

"I shall endeavor to do so." 

"Hey, don't be so casual about it."

Ascending the ice staircase, Kanata pondered:

(While I desire certain Devil Fruits...I can hardly consume them myself. Having powerful subordinates would certainly ease traversing these tumultuous seas without issue.)

Yes, that would likely prove difficult, she muttered softly.