Conquering Heroines: Starting From A World Of Zombies

Thin strands of Haki instinctively wrapped around the blade of Kashu, and in the next instant, flames erupted around Ryuji.

His attack reached Daz Bonez almost instantly.

"What the—?!"

The scorching heat hadn't even touched him yet, but Daz could already feel the unbearable temperature in the air. He immediately retreated, trying to evade the incoming strike. But he'd barely stepped back when the ferocious attack was already upon him.

His steel body—once his greatest defense—was torn apart in an instant. A gaping hole opened in his chest and abdomen, and his internal organs were incinerated by the overwhelming dragonfire, charred to ash in seconds.

Even as he staggered back, Daz's mind was still clear. But his body had already died inside.

He tried to retaliate, but no sound came from his mouth. Though he could still move, when his brain sent the command to fight, his body didn't respond with power—it simply collapsed to the ground.

Staring at the rapidly approaching earth, a single thought crossed his fading consciousness:

Didn't I dodge it…?

And then, pain—searing pain. The feeling of his organs catching fire all at once.

He couldn't speak. He couldn't breathe. His heart had stopped. Within seconds, his brain shut down from the drop in blood pressure.

Yes—this man, who had once pushed Zoro to the brink with his Dice-Dice Fruit, was killed in a single blow. Ryuji's slash, imbued with Haki, dragonfire, and a swordsman's mastery, ended him just like that.

"…Huh. I used Roger's technique by instinct, huh?"

Ryuji wasn't surprised. His dragonfire burned hotter than magma. Daz had taken it head-on, and his blade had pierced the fruit-user's defense, tearing through into his organs. Of course he died instantly.

If the guy had known Armament Haki, he might've lasted longer. But clearly, Daz had relied too much on his Devil Fruit, never learning the deeper arts.

To face a swordsman with Haki and Observation and assume your fruit would save you? You deserve to die in one stroke.

And Ryuji's dragonfire? It did true damage. Hotter than magma, crueler than any pain. Daz never stood a chance.

Had he dodged the flame, engaged in a prolonged fight? Sure, it would've been tougher. But no—he overestimated himself, and Ryuji took advantage.

"Overconfidence in your fruit… that's just asking to be punished."

Ryuji flicked his blade to clean it, eyes sweeping the horizon.

He was hoping crocodile would show up too. That way, he could end this whole mess in one go. If not, he could always take the fight to the sea and drown the man. As long as he killed all the witnesses, there'd be no evidence left.

But he saw no sign of the warlord. Not even a trace of sand.

His Observation Haki wasn't nearly as powerful as that of the guy that calls himself "god" who had eaten the Rumble-Rumble Fruit, after all. Its range was limited.

"I Didn't expect your strength had reached this level."

Robin was genuinely surprised. She had known Ryuji had been training relentlessly, but this? This level?

"He just got cocky," Ryuji replied. "Thought his fruit made him invincible. Otherwise, it would've taken a little longer. Besides… your world's power system is pretty interesting. Armament Haki or Observation Haki—this world favors people who strive."

Ryuji sheathed Kashu. He still preferred guns and greatswords to katanas, but he had to admit—this one could at least withstand his fire. It had only barely started to melt.

Impressive.

Steel melts over 1,000°C, well below magma temperature. His flames were far hotter. For this blade to survive at all?

It was more than a mere weapon—it was exceptional.

And then there was his Observation Haki.

Unlike how the anime portrayed it, his version felt different. It wasn't his sense—it was like the world itself whispered truths to him.

A unique feature of the One Piece world, just like the stat boosts in 7 Days to Die. It wasn't something he could bring into other worlds.

That made sense. Ryuji could freely adapt to other worlds, but the rules of each world didn't adapt to him.

It was like trying to import DNF character stats into League of Legends—utterly incompatible.

Each world had its own system. And this one?

He glanced at Robin's waist.

Beautiful. But, to be honest, it was almost too thin does not match her figure at all.

That was another clue—these powers, like Haki, weren't transferable. If he tried to use Observation Haki in another world, it would probably be nerfed to hell.

That's why he never really focused on these fancy skills.

His true strength was always his body—and his system skill tree. Everything else was decoration. If the world's rules shifted, those surface-level tricks would vanish.

Robin didn't argue. She had visited the 7 Days to Die world herself, experienced the suppression. She knew he was right.

"But be careful," she said. "Crocodile's not that easy."

Ryuji nodded.

He turned to find Vivi—when the ground beneath his feet suddenly collapsed.

A storm of sand exploded into the air. From several hundred meters away, a man with slicked-back hair slowly approached.

Too far for his Haki to detect.

By the time Ryuji felt the incoming sand, it was almost too late. But—

Flames erupted around him, countering the rushing sand. He drew his sword and hurled a vicious slash straight at the approaching figure.

The flaming strike tore toward Crocodile with terrifying force. The sand couldn't block the Haki-infused blade. Eyes narrowing, Crocodile raised his arm, summoning a wall of sand to intercept.

Layer after layer crumbled under the slash—until the final layer gave way, and a single strand of sword-wind slipped through, slicing a lock of hair from Crocodile's head.

"…Impressive flying slash. No wonder Robin followed you."

Crocodile's gaze narrowed. The flames around Ryuji made one thing clear—he was a Devil Fruit user.

But that wasn't all. His swordsmanship, his control of fire, the Haki in his attacks—this was no ordinary man.

Still—

This was his domain. The desert.

The port beneath Ryuji's feet had already been converted into sand. If Daz hadn't died so quickly, Crocodile might've been able to save him.

But it didn't matter.

Because fire? Fire was weak to his sand.

Crocodile smiled.

"I'll give you a choice. Hand over Nico Robin. Pledge yourself to me. And maybe—I'll let you live."

He turned to sand and rapidly approached, cigar in hand, as calm as ever.

At first, when Robin had requested leave, he thought she'd found another archaeological site.

But then he learned she wasn't doing research at all. Not only had her crew expanded, but she wasn't in charge. A nameless man was.

That was enough to confirm it—Robin had betrayed him.

And if she knew Crocodile's strength and still betrayed him, that could only mean one thing: this man—Ryuji—was no weakling.

So he gathered all of Baroque Works to test the waters.

But even so… Daz had died.

Still—no problem.

His sand countered Ryuji's fire. Ryuji's slash might have Haki, but Crocodile could react in time. This was the desert. His home turf.

Even a Navy Admiral would struggle here.

But—

Ryuji raised his blade.

"So you're the Crocodile, huh? I'm gonna borrow your head for a bit—gonna use it to pick up girls."

A violent slash, wreathed in blazing dragonfire, surged toward Crocodile.

This wasn't a warning shot—this was Ryuji striking for real.

Crocodile didn't dare take it head-on.

His body dissolved into a stream of golden sand, vanishing from view. At the same time, he extended his hand toward the ground beneath Ryuji—turning it into sand as well, trying to destabilize his footing.

He wasn't foolish. He knew better than to let Ryuji get close. The flying slashes were one thing, but a direct hit from that sword? That would be the end.

He wasn't facing some upstart like Luffy anymore. He was fighting a man strong enough to make Nico Robin switch sides.

Crocodile was taking this seriously.

He moved at full speed, body dispersed, voice silent.

But—within Ryuji's hyper-focused Observation Haki, every grain of sand, every flicker of movement, every intent was laid bare.

Crocodile's form might have turned to sand, but his intent remained crystal clear.

'I'm over here.'

Even the sand itself seemed to scream it out.

Ryuji smirked.

"Too slow, aren't you?"

His figure blurred—vanishing like lightning.

Flames streaked behind him like rocket propulsion. His blade struck with perfect timing, cleaving directly into Crocodile's sandy form.

Thin tendrils of Armament Haki wrapped around the edge of the blade, just enough to make contact—real contact.

Crocodile was blown away, reeling.

"W-What?!"

He stared in disbelief as Ryuji appeared right in front of him.

Too fast. Far too fast.

Before he could phase out, before he could react, the sword had already dug into his side—slicing through his ribs like butter.

With desperate precision, he twisted his sand and escaped—barely. Had he stayed a second longer, he would've been cleaved clean in half.

He tumbled through the air, blood trailing behind, before landing in the distance, clutching a blackened wound on his side.

His eyes, wide with disbelief, stayed locked on Ryuji.

How? How had that blade found him? How had it bypassed his defenses?

That Armament Haki wasn't even full-body coverage—it shouldn't have worked!

He knew Haki. He'd killed his share of Haki users in the Grand Line. What Ryuji had shouldn't have been enough.

And yet… it was.

That strike had felt more devastating than a Vice Admiral's blow.

His Haki was refined—sharp and lethal.

And then there was the Observation Haki.

That reaction time. That tracking ability.

And the fire… that flame wasn't ordinary. That wasn't fruit-based. It had the pressure of a Logia Awakening—perhaps even stronger.

And the swordsmanship?

The precision, the efficiency—it felt like the product of decades of training, not something a man barely in his twenties should have.

How was this possible?

Where had this monster come from?

Someone this dangerous… shouldn't be unknown!

"You… someone like you shouldn't be a nobody."

Crocodile struggled to his feet. The wound wasn't fatal—but fear had started to seep into his gut.

He'd realized something: he couldn't win.

Crocodile scanned the desert terrain. He had already begun planning his retreat.

He needed time. He would regroup, recover, call in reinforcements—break Ryuji down over time. He wouldn't risk it here, not injured and cornered.

But—

Ryuji, still wrapped in flame, stood tall, sword in hand. His Observation Haki was pushed to the limit—and in that moment, he felt it.

Crocodile's hesitation.

His plans. His escape route. His bluff attack. His fallback plan.

It all unfolded in Ryuji's mind in real time—as if Crocodile himself was speaking them aloud.

And then—visions. Previews of possible futures flashed before his eyes. Different reactions, different outcomes, different slashes. The wind shifted—and everything aligned.

The sand. The air. The dust.

Exactly as he'd foreseen.

Future sight. Mind reading. Communion with the world itself…

"Is this really… just Observation Haki?"

Ryuji blinked, momentarily stunned. This wasn't just sensing intent—this was full-on supernatural clarity.

He chuckled.

"Observation Haki… really lives up to its name."

And then he moved.

Because he already knew everything Crocodile was about to do.

Crocodile stared in disbelief as Ryuji skipped across his sand traps as if they weren't even there. He panicked, lunged with his hooked hand, tried to strike—but Ryuji was already past him.

The blade cleaved through the sand barrier.

A glimmer of Haki flickered again along the edge—light, almost invisible—and then it thrust forward, piercing precisely into a patch of air.

That—was where Crocodile was.

In a single moment, blood burst into the air.

Crocodile stared in shock as the tip of Kashu pierced through his chest, erupting from the front. He couldn't believe it.

He had been found. Not just found—defeated.

As if that man could see the future itself.

"How is this possible...?"

Ryuji calmly pulled his sword free, the molten edge searing through flesh. The blade had punctured Crocodile's lung—and scorched it from the inside. Breathing now would be nearly impossible. Defending himself? A joke.

And running?

A death sentence.

But Ryuji didn't finish him off.

There was a reason for that.

He needed Crocodile alive—as evidence. To prove his plot to overthrow the kingdom. A witness. A tool.

"Sorry," Ryuji said, glancing down at him. "But it looks like this world likes me a little more than it likes you."

"And the reason you lost? It's simple—you thought too much."

He didn't shut off his Observation Haki.

He wanted Crocodile to hear every word. To understand.

"You lost because you couldn't stop weighing your options."

Gain. Loss. Damage. Escape.

Everything except the fight in front of you.

"And let's be honest," Ryuji added, voice calm but cutting, "your hand-to-hand skills are trash. Your Haki? You don't even have a grip on the basics. Your will to fight? As soft as wet paper."

"You ran into someone who's got no gaps to exploit, and instead of standing your ground, you hesitated."

"You wanted everything. And you got nothing."

Just like when he lost to Luffy.

Crocodile had always been the same.

Too caught up in his own schemes to face reality head-on.

Luffy? He never stopped to think about odds. About logic. About what came next.

He only ever had one goal:

Beat the guy in front of me.

It wasn't smart—but it was pure.

And in this world?

In this story?

That kind of purity was everything.

"You really are something, Crocodile," Ryuji said, turning away as the warlord's body collapsed behind him. "You managed to get far. But you forgot the one rule this world doesn't forgive."

He raised his eyes toward the desert sky.

"In this world…you can do anything. Except lack conviction."

"That's the true lesson of One Piece."