One Piece : Marine Scientist

Marine Headquarters.

Inside Leon's private laboratory, a childish laugh echoed through the room.

"Ahahahaha! It's finally complete!"

Leon stared at a larger-than-usual incubation pod, his young face fill with anticipation.

"Come forth, Admiral-level Seraphim!!" he exclaimed, gently pressing the button in his hand.

The hatch of the oversized pod slid open.

Amidst a dissipating mist, a fully grown Seraphim stepped out slowly.

It bore the signature traits of the Lunarian Tribe—white hair, brown skin and a pair of black wings wreathed in flames.

Yet, there were distinct differences.

Its face was that of a younger Akainu and towering over the Warlord-level Seraphim, it even sported two dragon horns identical to Kaido.

The creature radiated an overwhelming aura of power.

"Perfect!" Leon beamed with satisfaction.

"Such a Humanoid Weapon deserves a name. Since you're the fusion of Akainu Sakazuki and Kaido lineage factors..." He paused dramatically.

"You shall be called Sakai!"

"Come, Sakai! Let's head to the testing grounds and see what you can do!"

Eagerly, Leon led Sakai to the testing ground.

"Start with a Laser Beam."

"Yes." Sakai nodded, slowly raising its right hand.

An intensely blinding light erupted, so bright it seemed to illuminate the entire sky.

Every Marine in Headquarters instantly turned their heads in shock.

The next moment, a Laser Beam shot from Sakai's palm.

With a deafening sonic boom, terrifying shockwaves of energy rippled outward, shattering every window in Marine Headquarters!

Simultaneously, as if transcending space itself, the Laser Beam detonated in the distance.

BOOM!!!

The entire island seemed to tremble from the force of the explosion!

"W-What was that?! A Yonko attacking us?!"

"Enemy attack! Enemy attack!"

Panicked cries erupted as the Marines paled in terror.

Immediately, the piercing wail of emergency alarms blared across the Marine Headquarters, and everyone sprang into action!

"All hands, assemble at once!" Sengoku voice was grave as he issued the order.

"You three—investigate immediately!"

"Yes!" The three Admirals moved without hesitation, leaping straight out of the windows and charging toward the explosion's origin.

Kizaru transformed into a streak of light and darted ahead.

The three Admirals arrived at the scene, confronted by a colossal crater stretching a kilometer wide and a hundred meters deep.

Black smoke and scorching heat still rose from its depths.

"Such destructive power..." The Admirals' faces grew grim.

Enemies capable of unleashing such an attack were few and most of them are far in the world.

"But..." Kizaru frowned in confusion. "Why does this attack feel... familiar? Almost like my Laser Beam ..."

Akainu and Kuzan turned to him, equally puzzled.

Just then, a familiar, childish voice called out.

"Brother! And Admiral Sakazuki and Kuzan! You came!"

"Huh?" The three Admirals turned in surprise.

There stood Leon, his youthful face beaming with pride.

"How about that? Not bad right?"

"Leon, how did you manage to..." Kizaru and the others was speechless.

Standing behind Leon was a figure that was, undeniably, a young version of Akainu.

But this one had white hair, brown skin and a pair of black wings wreathed in flames on his back.

"Wait! Is this an Admiral-level Seraphim?! You succeeded in developing it?!" Kizaru exclaimed, astonishment clear on his face.

Akainu and Aokiji were equally shocked.

A Den Den Mushi buzzed and Sengoku's voice crackled through.

"Borsalino, what's the situation? Which enemy is it? I've already mobilized the troops, ready to attack at any moment."

"N-no need, Fleet Admiral Sengoku" Kizaru quickly replied, snapping back to reality.

"It's not an enemy, it's Leon's invention..."

"Invention?" Sengoku sounded clearly taken aback on the other end.

"Yes, it's... an Admiral-level Seraphim! It's already been completed!"

"What? Hahaha, that's fantastic news! Wait for us, we're coming right away!"

Soon, Sengoku and Garp arrived eagerly.

"So this is the Admiral-level Seraphim?" Sengoku murmured, surprise and admiration filling his eyes.

"It's no longer in the form of a child and looks quite similar to Sakazuki in his youth..."

Garp on the other hand, stared at the Seraphim in astonishment, touching here and poking there.

"Not just similar—it's identical!" Akainu responded gravely.

"But do you know if its strength truly reaches Admiral level?" Akainu looked at Leon, skepticism in his voice.

"Then let's test it!" Leon met Akainu gaze, his small face showing not a trace of fear. Instead, he smiled confidently.

"Good, I was thinking the same!"

Leon turned to the Seraphim. "Sakai, fight Admiral Akainu. Show your true strength!"

"Yes!" the Seraphim responded.

"Sakai? A combination of Sakazuki and Kaido names? Quite fitting!" Vice Admiral Tsuru commented, having also arrived upon hearing the commotion.

"Hmph, let's fight first and talk later!" Akainu snorted coldly, his body enveloped in Haki.

He struck swiftly, holding nothing back, though he refrained from using his Devil Fruit abilities.

BOOM!

Sakai moved quickly, dodging Akainu punch with a swift tilt of his head.

Then, powerful Armament Haki coated its fist and it struck directly at Akainu!

BOOM!

Akainu reacted instantly, throwing a punch of his own to meet the blow.

As their fists collided, a violent impact resounded, forcing both back.

It was a deadlock!

"Incredible!" Akainu eyes flashed with astonishment.

In terms of raw strength and Armament Haki, he hadn't gained the slightest advantage.

"Again!" Akainu attacked relentlessly, engaging Sakai in fierce combat.

They exchanged punches and even clashed with swordsmanship—Akainu, a master swordsman in his youth, always carried a blade backthen.

But in every aspect, Sakai the Seraphim, was not the slightest bit inferior.

In fact, its endurance seemed slightly superior to Akainu and its terrifying recovery speed left him stunned.

"Huff... huff..." Akainu looked somewhat disheveled.

"Without using my Devil Fruit powers, I'm actually not a match for it! If we were to use my Devil Fruits power, I suspect it would still end in a draw..."

Akainu expression was utterly shocked.

The onlookers were equally astonished, they could all see it—the Admiral-level Seraphim truly lived up to its name, possessing the strength of an Admiral!