Demon Slayer Virgil [Isekai One Piece]

Boom, boom, boom.

The thunderous sounds of cannon fire echoed across the sea's surface. The gun deck at the bow of a naval ship was emitting wisps of smoke from the hot cannon barrels.

1,500 meters across from the naval vessel, a pirate ship was obliterated by the barrage, flames engulfing it as pirates either died, fled wounded, or abandoned ship entirely.

This was taking place in the latter half of the Grand Line, commonly referred to as the New World.

This region included one of the three initial New World islands - the vicinity surrounding Skypiea, the island under the thunder god Eneru's control.

Throughout these waters, numerous naval ships patrolled, led by Vice Admiral Onigumo "Demon Spider".

"Heh, these insolent pirates just don't know when to quit," Onigumo scoffed, exhaling a puff of smoke without an ounce of pity as he observed the burning pirate ship.

"Vice Admiral, a message from headquarters!"

"Hm? Let me see it."

...

In the first half of the Grand Line, a naval ship sailed swiftly across the sea, heading towards a particular destination.

"Rear Admiral Zavia, we've been sailing continuously for 7 hours now. The other men are starting to show signs of fatigue," a marine ran up to Zavia at the bow gun deck, his expression weary.

"Hmph, I know. There's an island up ahead where we can resupply and rest for a day," Zavia turned, eyeing the exhausted marine and the sun dipping close to the horizon.

"Understood."

Zavia was no monster or cruel man - he could be gentle towards his subordinates. But he was eternally cold and ruthless when facing enemies.

Perhaps it was the influence of his inherited power, or Vergil's lingering presence within him, but Zavia often felt conflicted.

The human and demonic sides of his nature were constantly battling, something Zavia had noticed a month after arriving in this pirate world.

Since then, Zavia found himself becoming increasingly callous, looking down on everyone - friends, superiors, all were beneath him.

He managed to catch himself before completely losing his way. But the demonic side still slowly reshaped him over time.

Zavia pointed northwest, informing the marine that there was an island not too far in that direction, about two hours' sail. With favorable wind conditions, they might arrive in just one hour.

Zavia wasn't guessing - he spotted the island with his superhuman eyesight.

As his training intensified, Zavia's physical abilities grew sharply, surprising himself at this apparent Saitama-like constitution.

The truth remained unclear, but Zavia hypothesized it related to his inherited demonic power - a power still shrouded in complete mystery to him. So far, he only knew it was some form of inherited ability.

...

Outside their world, in the cosmic realm surrounding a planet teetering on the brink of collapse, two blurred figures clashed.

Like beams of light, they collided and separated repeatedly, colliding again before parting ways in an endless cycle of impact.

KRAAABOOOOOOM!

A tremendous shockwave rippled out as one of the blurred streaks plummeted, slamming into the ground and kicking up a massive dust cloud. It carved a trench dozens of meters long before finally grinding to a halt.

"Cough! Hah...hah...wh...why?"

As the dust settled, a black-haired swordsman in light armor lay prone, coughing up blood as he glared up at the other figure.

"There is no why. You are irrelevant to our master's chosen inheritor. You were not destined for his trials, yet you sought to take his life?"

The figure above slowly descended - black hair, black and white robes, an ethereal emissary from the heavens.

"Cough cough! Hmph, that's...none of my...concern. I merely...followed orders..." The swordsman spat out a mouthful of blood and let out a mocking laugh, seemingly disdainful of his opponent.

"Alas, and so for such a trivial command you earn our ire? How foolish." The robed man showed no emotional response to the swordsman's taunts, his expression one of pure contempt for the other's answer.

"Enough prattle. Following orders seems the only value you possess." As the last words left the robed man's lips, blue particles began coalescing in his hand before the swordsman could finish his retort. He clenched his fist, instantly crushing the man's skull.

"Tedious. I should hope matters progress more swiftly elsewhere. After all, I've already cast that 'object' into that world."

The robed figure flicked his wrist dismissively before turning his gaze skyward, muttering thoughtfully to himself.

...

After a brief respite, Zavia's subordinates seemed much more energized.

"Rear Admiral Zavia, approaching Jaya Island dead ahead!"

"Jaya Island, huh...Could that ominous presence be connected to this place? Hmm...bring us in closer to the island." After a moment's contemplation, Zavia gave the order to dock at Jaya.

"But sir..." The marine seemed to have some reservations, hesitating.

"Sigh, today all of you can take some shore leave on the island. Go have fun." Using the prospect of leave as an excuse, Zavia waved off the marine, overhearing an excited remark as he departed.

As a marine officer, Zavia knew full well that Jaya Island was a famous resort destination - just one that catered predominantly to pirates, with the Navy rarely visiting.

"So, how should I approach this..."

Once alone, Zavia began contemplating what unknown secrets the island might hold from the original story. Try as he might, nothing came to mind that suggested anything earthshaking lurked on Jaya itself.

Unless...

"Could it be on the sky island above?" Considering that possibility, Zavia tilted his head skyward, his gaze inscrutable.

"Tch, if it's really on that sky island, that complicates matters. Putting everything else aside, just getting up there is a headache." Realizing the potential hassle, Zavia shifted from standing to sitting.

The sky island was a place Zavia had longed to visit, for it harbored something he greatly desired - the Gura Gura no Mi, the Tremor-Tremor Fruit.

Among all the Logias, this was undoubtedly the most powerful Devil Fruit ability tied to nature itself.

But when Zavia realized that the time was 3 years before the start of the main plot, he gave up pursuing it, since Eneru had already consumed it - it was unattainable.

"Whatever, I'll explore Jaya first. With Valona's and my intervention, the story has diverted somewhat from the original. Maybe there are clues left behind here."

Putting those troubling thoughts aside for now, Zavia focused his gaze on the rapidly approaching island.

Two hours later, the naval ship neared the shores of Jaya Island. Following Zavia's orders, they anchored a reasonable distance away from the pirate ships, but not too far from the port itself.

As soon as Zavia disembarked, a man dressed as a resort staff member approached. "Welcome, esteemed military officer. Our humble town is honored by your presence."

"Yeah, I'm here to let my men take some leave. Lead the way," Zavia tossed a money pouch to the man, who deftly caught it and swiftly pocketed the funds.

"Why, of course! If the fine marines simply wish to enjoy themselves, right this way sirs!" Having received payment, the man's demeanor became even more ingratiating, his gestures more exaggerated.

Ignoring the overeager staff member, Zavia turned to address one of his marines. "You, take some men and go with him. Have the rest join us after getting squared away."

"Sir? What about you?"

"I have some business to attend to first. Don't wait up, take the men and go enjoy yourselves." Patting the marine on the shoulder, Zavia headed off in the direction of the forest.

"I see..." The marine watched Zavia's retreating figure with a resigned expression.

"This way please, sir marine!" The staff member's tone became obsequiously respectful upon learning Zavia was a Rear Admiral.

(Didn't expect a mere Rear Admiral to be so young. The Navy is really cultivating monsters these days?)

The staff member's gaze lingered on Zavia's departing form, his inner thoughts a mixture of surprise and wariness.

...

"Tch, the Navy? Can't believe they'd show up in a place like this."

As Zavia proceeded, numerous pirates shot him disdainful, contemptuous, or hateful glares.

Clearly they recognized him as a marine officer - hardly surprising given his white Navy coat with the word 'Justice' emblazoned on the back. One would have to be blind or stupid not to identify him.

"Way I see it, he's probably here to arrest someone."

"Could be. Any idea who he's after?"

"How should I know? Why don't you go ask him? Maybe he'll actually tell you."

"..."

The idle chatter reached Zavia's ears, but he paid it no mind.

He had anticipated the reception a Navy officer would get on this pirate haven. But he felt no trepidation - at this point in the story, the island lacked any real threats to be concerned about.

While he couldn't guarantee his subordinates' safety, Zavia remembered a certain someone was also present, putting those worries to rest.

"Tch! What's the big deal? It's just one measly Navy dog!"

A hulking, brutish figure at least 2.5 meters tall abruptly blocked Zavia's path, a massive cleaver-like blade in hand. A gang of around 10 more pirates trailed behind him.

"Hey Kalus, you sure you wanna mess with a Navy officer? He might try arresting you," one of the lackeys mocked derisively.

"Hah! Arrest me? I'm Kalus Qis, with a bounty of 37 million beris! You think this scrawny dog could arrest me?"

The man named Kalus swung his large blade menacingly as he announced his epithet with an air of bombast.

"Get lost, you fat pig. You're in my way."