Onepiece: I Am Aizen, The Strongest Admiral

"Go to hell!"

Marco's voice roared through the air as he descended from the sky. His right leg, wreathed in blue flames, hurtled toward Aizen with unrelenting force. Just before the strike, his leg shimmered with a dark sheen—**Armament Haki**.

Though merely an intern on the Whitebeard Pirates' ship, Marco had already grasped the basics of Haki under the guidance of his crew.

Aizen, however, remained calm. He raised his Zanpakutō, positioning it across his face.

**Boom!**

Marco's full-force attack collided with Aizen's blade, only for the fiery assault to be neutralized effortlessly. No fancy techniques—just the pure, controlled power of the Zanpakutō.

"To block my attack so easily... and with such precise control of power?" Whitebeard's brows furrowed as he observed the clash. While he anticipated a gap in strength between Marco and Aizen, seeing it manifest so vividly was startling.

"Damn it! Don't act so self-righteous!" Marco growled, his frustration evident as Aizen stood unshaken.

Unfolding his azure wings, Marco took to the air again. This time, his arms glimmered like twin blades as he launched another assault.

**Slash!**

A flash of blue light streaked through the battlefield. Marco barely registered what had happened before stumbling to the ground, a searing wound on his chest.

Phoenix flames erupted, enveloping Marco as his body attempted to heal itself. The Whitebeard Pirates' captains watched with bated breath, their tension easing slightly when they saw the flames ignite.

"As long as the phoenix flames burn, Marco will recover," someone muttered.

But Marco's expression betrayed his growing dread. "What... what is this? My recovery speed... it's slowed to a tenth of what it was!"

He looked down at his injury, his voice trembling. The moment Aizen had drawn his Zanpakutō, Marco couldn't even see the blade—only the flash of light before he collapsed. And now, his wounds weren't healing as they should.

"I've suppressed your recovery with my Reiatsu," Aizen said coldly, stepping closer. "Yield, and this ends here."

Marco gritted his teeth, refusing to submit. Yet, as he prepared to retort, an overwhelming force pressed down on him—a crushing wave of Reiatsu.

Suddenly, Aizen's presence felt impossibly distant, like a demon from the depths of hell.

"If you think my Reiatsu is limited to slowing your recovery, you're mistaken," Aizen continued, his voice like ice. "I can halt your regeneration entirely. Your so-called immortality would be useless."

Marco's defiance crumbled under the weight of Aizen's words and power. "I... I lost," he admitted, though the bitterness in his voice was unmistakable.

The system's voice echoed in Aizen's mind:

**[Defeated future Whitebeard Pirate Commander Marco. Template unlocked: 15.3%.]**

Suddenly, Whitebeard's laughter boomed across the Moby Dick, breaking the heavy atmosphere. "Gurararara! Marco, losing is just part of growing stronger. Keep working hard."

The old pirate showed no anger toward his subordinate's failure. This fight was meant to teach Marco about the vastness of the world.

Turning to Aizen, Whitebeard's gaze sparkled with admiration. "You're impressive, kid. The more I see, the more I want to make you one of my sons. How about it? Abandon the Marines and bear my name instead."

Whitebeard's offer carried weight—he rarely extended such an invitation, which spoke volumes about Aizen's strength.

But Aizen didn't hesitate. "I'm Marine." His response was firm, leaving no room for negotiation.

Whitebeard chuckled, undeterred. "Sticking to your path, eh? Those Marines are lucky to have you. Mark my words: within ten years, you'll be a Marine Admiral. Less than thirty and already an Admiral—that's no small feat."

The crew fell silent, awestruck by Whitebeard's praise. It was rare for him to speak so highly of anyone, let alone a Marine.

"Marine Admiral..." someone murmured.

The title carried immense weight, reserved for the strongest individuals who could hold their own against the likes of emperors. And here was Whitebeard, proclaiming that Aizen would achieve it before long.