The voice that echoed in Robin's mind sent a shiver down her spine. It was a strange sensation, one that felt both comforting and ominous. The voice seemed to come from everywhere, resonating through the very walls of the cavern, but it was unmistakably familiar.
"Robin… You're not ready for this."
Her hand trembled as it rested on the glowing altar. The crystal's pulse beneath her fingers was strong, but the voice's warning had struck her at her core. It was as if the island itself was speaking to her—doubting her ability to control its power.
"Who… who are you?" Robin whispered, her voice echoing in the stillness of the cavern.
The voice answered, low and reverberating. "I am the essence of this island, the guardian of its ancient secrets. The crystal was not meant to be sealed, nor should it be controlled. You do not understand the consequences."
Robin's brow furrowed in confusion. "But I do understand. The crystal is a power that must not fall into the wrong hands. Arcturus is dangerous. If he controls it, he will—"
"He will do nothing." The voice interrupted, its tone cold and resolute. "The crystal's true purpose is not to be wielded by anyone. It was meant to exist in harmony with the island. To attempt to change that harmony is to risk the destruction of both. You are not ready to bear such a decision."
Robin's mind raced. Was the island telling her that sealing the crystal was wrong? Could it truly be that the island's power was a force that should remain unchallenged, even if it meant allowing such a dangerous figure like Arcturus to claim it?
She had come to understand the responsibility of wielding knowledge and power—she had spent years seeking knowledge, and now she was being asked to understand something far greater. Could she trust in the will of the island, or would she go against it to protect the world?
"Robin!" Luffy's voice snapped her back to the present, urgent and unyielding. "We need you to hurry up! The guardian's not slowing down!"
The rumbling of the cavern intensified as the massive stone creature continued to attack, its heavy steps shaking the ground. Zoro and Sanji were still holding their ground, fighting the guardian with everything they had, but the creature was resilient, its body repairing itself with each strike.
Robin's gaze shifted to Arcturus, who was standing by the altar, his hands raised as he continued to manipulate the island's power. He had no intention of stopping, his cold smile growing wider as he sensed victory. "You think you can stop me, Robin? The island is mine, and so is the crystal. The power of this place will bend to my will."
With each word, Arcturus' control over the island seemed to tighten. The guardian became more aggressive, its form crackling with energy. Robin could feel the weight of the island's power, pulling her in two different directions—one urging her to trust in the island, and the other telling her to stop Arcturus at any cost.
But what if she could do both? What if the island itself didn't want the crystal sealed away forever, but needed to be protected from those like Arcturus?
The decision weighed heavily on her shoulders, and as the voice in her mind grew more insistent, Robin closed her eyes, pushing aside the doubt. She knew that she couldn't allow Arcturus to win, but she also couldn't allow the island's power to be abused.
The runes on the altar began to glow brighter, and Robin took a deep breath. "I'm not here to control the crystal. I'm here to protect it."
With that, she slammed her palm down onto the altar with all her might, releasing a burst of energy that vibrated through the cavern. The guardian paused, momentarily disoriented, as the flow of power shifted.
Robin felt the ground tremble beneath her feet. She was no longer just sealing the crystal away; she was re-establishing the island's balance, reconnecting the crystal to its true purpose. The power surged through her, overwhelming but not all-consuming.
"You've made a mistake, Robin," Arcturus sneered, stepping forward. "The island belongs to me now. Your resistance is meaningless."
But as he stepped toward her, the entire cavern seemed to shake, as if the island itself was rejecting him. The walls of stone began to crack, the glow of the crystals pulsating with fury. Arcturus froze, looking around in alarm.
The island had begun to fight back.
Robin could feel it—a tremendous force stirring beneath her feet. The pulse of the crystal was no longer a threat; it was a call to action, guiding her movements. She pressed forward, her eyes locked onto Arcturus, who was now struggling to maintain his control.
Zoro, Sanji, and Luffy, seeing the shift in the atmosphere, took advantage of the moment. Luffy, grinning, dashed forward and punched the guardian square in the face with a force that sent it staggering backward.
"Let's finish this, guys!" Luffy shouted, his confidence unwavering as he launched into action.
Zoro and Sanji followed suit, with Zoro delivering a final, powerful blow to the guardian's chest, splitting its rocky exterior wide open. Sanji used his powerful kicks to land decisive hits, sending the creature into the ground with a thundering crash.
But as the guardian collapsed, Arcturus screamed in frustration. He began to focus all his energy into one final attack, a dark wave of destructive power aimed directly at Robin and the altar. The entire cavern shook violently as his power surged, the air thick with the promise of devastation.
Robin's heart raced, but she didn't hesitate. She raised her hands toward the altar, calling upon the island's power to counter Arcturus's attack.
With one final, resolute push, the island responded. The dark energy Arcturus had summoned was absorbed into the crystal, leaving him vulnerable for just a moment.
"Now, Luffy!" Robin shouted.
With a roar, Luffy charged forward, using all his strength to deliver a massive punch directly to Arcturus's chest. The force of the blow knocked Arcturus backward, sending him crashing into the cavern wall, defeated at last.
The island fell silent, the crystal's glow dimming as its power returned to balance. The threat was over—at least for now.
Robin breathed a sigh of relief, her body exhausted but relieved. She looked around at her crewmates, all of them battered but victorious. "We did it."
But as they began to catch their breath, they all knew that this victory wasn't the end. The crystal's power was far from fully understood, and the world beyond the island still held many dangers.
"Let's get out of here before anything else happens," Zoro muttered, wiping the sweat from his brow.
And with that, the Straw Hat Pirates began to leave the heart of the island, the crystal now safely out of Arcturus's reach—but still a force that needed to be carefully guarded.
To be continued…