"It's decent insight, but it's still just a prototype."

Caelan spoke calmly, not hiding his shortcomings.

After learning the method of training Conqueror's Haki coating from Rayleigh, he had been practicing it diligently.

Through nearly a month of focused training, and by referencing the techniques used by the Four Emperors, he had made considerable progress.

While it was still far from fully mastered, it was already showing results when applied.

At the very least, it was more than enough to deal with Doflamingo.

Caelan glanced at Shusui in his hand. The blade gleamed with a smooth, spring-like clarity—truly a top-tier famed sword.

Caelan brandished Shusui again, slicing through the white lines around him in a single sweep.

This white line technique made for a good testbed to gauge the power of his incomplete Haki coating.

"Damn it!"

Doflamingo's face was grim, teeth clenched in frustration.

His white strings couldn't even slow Caelan down. They were no more threatening than a child's toy.

He increased the density of the white strings, hoping to pose at least some level of threat.

But against Shusui, now enhanced by Caelan's Haki, the threads were easily shredded.

"Now then, you should be careful."

Caelan looked at Doflamingo, a smile tugging at his lips.

The experiment was over. He had a firm grasp of his current strength using Conqueror's Haki. There was no longer any need to play games with Doflamingo.

"What!?"

Doflamingo, who had been sending out strings on autopilot, suddenly sensed something was wrong.

Just as he was about to react, he realized—Caelan had vanished from his field of vision.

He immediately activated Observation Haki, straining to detect movement nearby.

"Slash!"

With explosive strength and blinding speed, Caelan appeared next to Doflamingo in an instant.

Then he brought Shusui down in a devastating arc.

Doflamingo's Observation Haki only caught the afterimage. Caelan had already closed in.

Panicking, Doflamingo summoned thick, layered white strings into a massive shield several meters thick.

Its defense at that moment was stronger than a fortress wall.

At the same time, he struck back with a counterattack, launching his ultimate technique.

Sixteen dense threads surged up from the ground, each reinforced with high-level Armament Haki, and all shot toward Caelan.

"Rapid Slash!"

Caelan remained composed. With a firm grip, his veins bulging, he clutched Shusui tightly and unleashed a flurry of wild, storm-like slashes.

The sixteen thick threads, enhanced with Armament Haki, were destroyed in an instant by the relentless barrage of cuts.

His overwhelming power and speed erupted all at once.

Boom!

With the sixteen holy threads annihilated, Caelan raised Shusui high and slammed it down on the massive shield of white strings.

Most of the five-meter-thick shield shattered on impact.

Then came a second strike—faster than lightning.

Caelan swung Shusui again, bringing it down upon the remaining shield structure.

Boom!

The last of the shield burst apart under the slash. Shusui's momentum slowed just slightly before it continued downward, straight at Doflamingo.

"No!"

Doflamingo's eyes were bloodshot as he watched Shusui cleave into his chest.

The blade sank two inches deep—nearly cutting him in half.

"Ahhh!"

Doflamingo screamed in agony as he quickly manipulated his strings to pull himself a hundred meters away.

In a single exchange, he had been utterly crushed by Caelan's sheer brute force.

"Haha, that's more like it."

Caelan shook the blood off Shusui casually, not bothering to chase him.

Out of the corner of his eye, he spotted a Marine soldier about to be killed by Donquixote grunts.

He casually flicked his blade, sending out a slash that turned the enemies into a mist of blood.

"Caelan-sama!"

The morale of the Marines surged. They shouted his name with reverence, treating him like a god.

He had just fought Doflamingo—one of the Seven Warlords of the Sea—and seriously injured him in a single exchange.

And still, he had time to protect ordinary soldiers during battle.

Such strength and care for his subordinates made them feel beyond proud to follow him.

For a while, the Marines charged with unrelenting fury, beating the Donquixote troops until they were screaming for mercy.

"Mm."

Caelan simply nodded and turned his gaze back to Doflamingo.

By now, Doflamingo was lying on the ground, struggling to breathe.

The terrain affected by his awakened Devil Fruit powers had also returned to normal due to the injuries he'd sustained.

"So weak."

Caelan curled his lip in disdain.

He hadn't even had enough fun, and Doflamingo had already collapsed.

Some pirate you are.

What happened to your legendary endurance?

A real man should be tough and resilient.

Only those who can do sit-ups endlessly and stand tall, like himself, deserve that title.

Looking at Doflamingo in this state, Caelan didn't finish him off.

The guy's former identity as a Celestial Dragon could still be useful.

"Cough…"

Doflamingo spat blood onto the ground, eyes full of disbelief as he stared at Caelan.

He had nearly died.

So this was the God Slayer—the one even the World Government couldn't suppress?

Doflamingo's pupils dilated with dread. He felt completely powerless in front of Caelan.

He had gone all out, and it was still meaningless.

He couldn't even block two of Caelan's ordinary sword swings. Even with Observation Haki, all he could see was a blur.

And even during their fight, Caelan had the leeway to help his subordinates.

The gap between them was like heaven and earth.

Could it be that Caelan really was invincible?

Doflamingo felt as if he had fallen into an endless abyss. His body went cold.

"Cough!"

He coughed up blood again, unable to keep thinking clearly due to the pain.

Clutching his chest, he used his strings to sew his gaping wound shut, doing emergency treatment to stabilize his injuries.

But just as he finished, he heard the agonized screams of his men echoing across the battlefield.

(To be continued.)