Aboard the Doberman, the second warship in the Buster Call formation, chaos reigned.
"Fire on the port bow! All hands, to emergency stations!"
"What's happening? Why is Admiral Jaga's ship coming straight for us?!"
"It's out of control! Sir, what are your orders?!"
On the bridge, a man stood amidst the panic, as calm and still as the eye of a hurricane. He wore the immaculate white coat of a Vice Admiral, a cigar clenched firmly between his teeth. His long, dark hair flowed from under his officer's cap, framing a face dominated by a thick beard that grew from his sideburns down to his chin. This was Vice Admiral Yamakaji, a veteran swordsman and one of the five commanders of the Ohara Buster Call .
He took a slow drag from his cigar, his eyes narrowed on the approaching fire-ship. "Can we outrun it?" he asked, his voice a low, steady growl.
"Negative, sir!" a panicked helmsman replied. "She's coming too fast! We can't evade in time!"
"Then we don't run," Yamakaji said, his decision absolute. He exhaled a plume of smoke. "All batteries, open fire. Sink that wreck before it touches my ship."
But they never got the chance. Before the gunnery crews could even aim their cannons, a deafening screech of tearing metal ripped through the air, followed by a thunderous crash from the forecastle. The entire warship shuddered from the impact.
"Report!" Yamakaji barked.
A terrified marine burst onto the bridge, his face ashen. "Sir! Our main cannon! It's… it's gone!"
Yamakaji's eyes widened fractionally. "What do you mean, 'gone'?"
"Someone… something… just ripped it off its turret!"
A vein pulsed in Yamakaji's temple. He strode out of the command cabin and onto the main deck, his hand already resting on the hilt of the katana at his waist. The sight that greeted him was one of pure pandemonium. His men were screaming, pointing toward the bow. There, standing where the ship's forward cannon should have been, was the man in the ridiculous theater costume. And he was holding the cannon—a multi-ton piece of siege artillery—as if it were a baseball bat.
"I believe this belongs to you," Captain America said, his voice ringing with challenge. With a roar, he swung the massive cannon barrel, using it as a colossal club.
Impossible, Yamakaji thought, his mind racing. The strength required to even lift that, let alone wield it… it's the power of a giant.
But a Vice Admiral of Marine Headquarters does not panic. He acts.
SHING!
Yamakaji's katana left its sheath in a blur of motion too fast for the normal eye to follow. It was a simple, perfect draw-and-cut, an Iai strike imbued with the full force of a master swordsman. The air itself seemed to split before the blade. The hardened steel of the cannon barrel offered no more resistance than bamboo. It was sliced cleanly in two, the pieces crashing to the deck with a deafening clang.
"Impressive," Captain America said, a note of genuine respect in his voice. He tossed aside the ruined remains of the cannon.
Yamakaji settled into a low stance, his blade held ready. "You have my attention," he said, his voice dangerously quiet. "Who are you?"
Riven felt a surge of adrenaline. This was no mere Rear Admiral. This was a true powerhouse of the World Government. He slapped a hand against his chest, the star a beacon of defiance. "I am a hero who stands for justice! They call me Captain America!"
Yamakaji's brow furrowed. He'd sailed the Four Blues and the Grand Line. He knew the names of emperors, warlords, and revolutionaries. He had never, not once, heard of a 'Captain America'.
"A nobody, then," the Vice Admiral concluded, his expression hardening. "It doesn't matter. By attacking a Navy vessel, you have declared yourself an enemy of the World Government. By order of Absolute Justice, I will execute you where you stand."
He moved. It wasn't Soru, but a swordsman's dash, faster and more fluid. His blade became a silver arc, aimed to cleave Riven in two.
This time, Riven didn't dodge. He charged forward to meet the attack head-on. He raised his shield, a small, circular buckler against the deadly sweep of a master's katana.
CLAAAAANG!
The sound was unlike anything anyone on the ship had ever heard. It wasn't the sound of steel on steel. It was the sound of an unstoppable force meeting an immovable object. A high-pitched, resonant chime echoed across the sea, a pure, perfect note of absolute impact.
The katana stopped dead.
Yamakaji felt a shockwave of kinetic energy explode from the point of impact. It surged up his blade, bypassed his guard, and slammed into his arms with the force of a battering ram. The recoil was so violent, so utterly absolute, that his hands went numb. He was thrown backward, his prized katana nearly torn from his grip. He stumbled, his arms trembling, his mind reeling in disbelief.
He stared at his blade. The edge, which could slice through cannon barrels, was not even chipped. Then he stared at the shield.
It was perfect. Pristine. Not a scratch, not a dent, not a single mark to show it had just met the full force of a Vice Admiral's strike.
"What…?" he whispered, his professional composure finally cracking. "That's impossible."
His mind, trained to analyze and overcome any foe, cycled through the possibilities. His strength is abnormal. His shield is… wrong. What is it made of? It can't be steel. Could it be a Devil Fruit ability? No, he swam here. Then… Seastone? The idea was absurd. A shield made of pure Seastone would be impossibly heavy, and it wouldn't have that resonant property. It would just absorb the impact. This… this threw it back.
"My blade can cut a warship's mast in half," Yamakaji said, his voice a mixture of fury and genuine, scientific curiosity. "And it could not leave a single mark on your shield." He looked at Riven, truly seeing him for the first time not as a fool in a costume, but as an unsolvable, terrifying puzzle. "What in the world are you?"