As one Goliath charged, Jack tapped into the fourth level of his techniques. The Phantom Dash activated, and he became a blur of motion. Darting around the beast, he struck it with lightning-speed punches, each blow leaving a shockwave in its wake. The creature grunted, trying to locate its agile foe, but Jack was always one step ahead, the sheer force of his Flash Step leaving the Goliath disoriented.

Lysander, for his part, was a sight to behold. With a powerful Levitation Leap, he soared high and then descended rapidly, infusing his Meteor Punch with the full weight of increased gravity. The impact on the Goliath was devastating. Bones cracked and the floor beneath it shattered. Not wasting a moment, Lysander decreased the gravity around his leg and unleashed the Nebula Sweep, his foot connecting with another Goliath's ankle, lifting it off the ground, rendering it momentarily weightless before crashing it down.

Two Goliaths attempted a combined attack on Jack. He responded with the Sky Splitter. A monumental punch ensued, unleashing a shockwave so forceful it halted their advance. The Goliaths staggered, the concussive force pushing them back, their immense size working against them. Realizing the need for a more direct approach, Jack prepared the Sky Annihilator. A barrage of Sky Shatterer punches rained upon one Goliath, the successive shockwaves overwhelming it until it collapsed, defeated.

Spotting a Goliath charging towards Lysander, Jack swiftly activated the Ghost Guard, becoming intangible and positioning himself between the creature and his comrade. The Goliath's attack harmlessly phased through him, and Jack seized the opportunity, employing the Spectral Barrage. A relentless series of phantom punches battered the creature, each blow leaving it more battered than the last.

Lysander, having momentarily repelled his own foes, smiled appreciatively at Jack. "Good timing."

A snort was Jack's only reply as he summoned the Sky Shield, deflecting an overhead smash from another Goliath. Lysander employed the Black Hole Grasp, his palm becoming a center of intense gravitational pull, redirecting a Goliath's momentum and sending it crashing into another.

Soon, the massive chamber echoed with the groans and roars of the fallen Goliaths. The duo, though vastly outnumbered, had the upper hand thanks to their agility, technique, and teamwork.

From the shadows, Caesar emerged, the hubris evident on his face replaced by realization. "You... you've dismantled my creations," he murmured, taking a step back.

Jack walked slowly towards him, the calm blue of his eyes unyielding. "You thought sheer size and strength would be enough? These Goliaths were your last line of defense, and now they lie defeated."

With a crazed expression, Caesar yelled, "Last line of defense?! Far from it!" He brandished a remote with a conspicuous red button.

Lysander's eyes widened in genuine alarm. "Don't!" But his warning was too late. As Caesar slammed down on the button, the room underwent a breathtaking transformation.

The ground beneath them started to shake, then suddenly dropped, descending at an alarming rate. Jack and Lysander, their combat instincts kicking in, steadied themselves. The walls of the chamber receded, expanding the room's size. Above, the ceiling was replaced with a shimmering, radiant barrier, diffusing the light in the room. The previously solid floor now bore arcane symbols, glowing with an eerie light.

Caesar's maniacal laughter echoed as a platform underneath him started to rise, positioning him at the very center of the vast expanse. "Welcome to the Omega Defense Mechanism!" he exclaimed, triumphant.

Jack frowned, surveying the situation. The room felt different, more hostile. His innate sense detected the oppressive weight of the sea stones lining the walls, rendering their Devil Fruit powers null and void.

"Damn it," Lysander murmured, realizing his abilities were compromised.

Caesar sneered. "Impressed yet?"

Before they could reply, crystalline pillars emerged from the room's perimeter, connecting overhead to form a radiant dome, casting the room in a surreal, prismatic glow. Jack tried to focus, but the environment shifted constantly. The tiles beneath them shuffled, creating a maze-like terrain. Every step, every move, had become a challenge.

Lysander clenched his fists, eyes darting around, assessing the new threats. "Jack," he whispered, his voice cautious. "Stay close."

As if on cue, illusions started to appear, duplicates of Jack and Lysander, weaving in and out of the labyrinthine paths. Hidden compartments opened, and high-pitched sounds filled the room, designed to disorient and distract. The Mirage Mirrors were at play.

Jack’s calm, analytical eyes noted the real threats amongst the illusions, his warrior instincts keeping him grounded. Panels in the walls slid open, and nets charged with electricity shot out, hovering menacingly.

But what truly captured their attention were the beasts emerging from hidden chambers. Chimera Guardians, products of Caesar’s twisted experimentation, advanced towards the duo with predatory intent.

Ceiling compartments released charged nets, ready to ensnare them, and trapdoors on the floor hinted at more danger lurking beneath. Still, neither Jack nor Lysander showed any intention of retreating.

"Thought your Goliaths were something?" Caesar cackled. "You haven't seen anything yet."

Lysander, eyes narrowed, responded, "All this theater, Caesar, and still, you'll lose."

Standing outside the intimidating edifice that guarded the island, the two warriors took a moment to regroup. The massive energy dome shimmering in the daylight caught Lysander's eye. He could sense the power pulsating from it, a power that wasn't purely physical, but something more intricate.

Lysander shifted, taking a deep breath. "That, Jack, is the Prism Barrier. Crafted from rare crystals sourced from the mysterious depths of the New World," he began, gesturing toward the shimmering shield.

Jack observed the barrier, his calm blue eyes taking in every detail, attempting to decipher its workings. The way the light refracted off the surface, splitting into countless angles, provided the initial hints.

Lysander continued, "Whenever an energy-based attack strikes this barrier, it's refracted, scattered into a plethora of angles. The result? The attack's potency is diluted, becoming all but ineffective."

Jack's eyebrows slightly furrowed in thought. "So it's not just a simple shield. The barrier itself manipulates energy, diffusing it."

Lysander nodded, his eyes flashing with respect for the brilliant minds that had crafted such a marvel. "Exactly. But it doesn't just stop there. Depending on perceived threats, the barrier can adjust its transparency. When under severe threat, it can turn completely opaque, obscuring everything behind it."

Jack tilted his head slightly, analyzing. "A dual advantage: protection and deception."

Lysander smirked, "Quite. Attackers get a distorted view of the real scene. It's disorienting and makes targeting accurately a massive challenge. If you’re not familiar with its tricks, you’re essentially flying blind."

Jack ran a hand through his hair, processing the information. "Vegapunk's work, I presume?"

Lysander chuckled, "Of course. Only his genius could conceive something so intricate and effective."