The battlefield roared with confetti and noise. The clash between Yuen and Alvionna had become more than just a duel—it was a spectacle that held the entire academy breathless. From the sidelines, Selion and his friends followed every movement with unblinking eyes, fists clenched in support of their comrade.
Suddenly, Alvionna raised her hand, summoning Bastor back. The massive robot stomped toward its master, its heavy steps shaking the ground. Yet she did not call him back merely to retreat; instead, she leaned close and whispered into the ear of her dinosaur-like construct. At once, it spread its wings and soared into the sky.
The mage beside her lifted his staff, the rune stone at its tip glowing bright, before hurling a volley of fireballs at Yuen. Instinctively, Yuen began to summon his magic—
But then…
A low vibration rumbled through the air, spreading from the body of the flying beast.
A piercing shriek cut through the battlefield.
The dinosaur's shrill cry sliced the sky apart, stabbing straight into Yuen's ears like daggers. He cried out, clutching his head in pain, his spell collapsing in his throat. In that instant, the fireballs struck him. At first they looked no bigger than sparks, but upon impact they erupted into thunderous explosions. Smoke and dust blanketed the arena.
The crowd froze. Children, teachers—even Headmaster Gareth—held their breath.
Alvionna stepped forward, a smug smile curling her lips.
— "You must have underestimated my creations. Let me enlighten you… My dinosaur's cry is more than enough to hunt down weaklings like you. As for my mage—his staff's rune stone contains more mana than most high-level sorcerers can hope to wield, allowing him to unleash even the simplest elements with devastating power. And Bastor…"
She pointed toward the hulking figure.
— "My tank. Beneath its heavy armor lies a rune stone brimming with barrier magic. Its body is already durable—but with the barrier layered on top, it becomes a true fortress."
Her words echoed across the training grounds, the audience listening in rapt silence. Only Selion and his friends looked on with something else in their eyes—not just awe, but concern. They knew this battle was far from over.
While her words still hung in the air, the smoke from the blast began to stir. Hidden within, Yuen was rising. Slowly but steadily, he found his breath, his eyes glowing with renewed determination.
The time for seriousness had come.
He had always known this fight would be difficult. Yet standing against Alvionna in the flesh, feeling her relentless pressure, was far more terrifying than he had imagined. Pushing the fear down, he clenched his fists—and then roared:
— "Underwater Vault! Second Form!"
The crowd's murmur fell silent. Alvionna narrowed her eyes; the weight in Yuen's voice was enough to unnerve her. This boy was no ordinary opponent.
Water burst from the ground, surging like tidal waves. It encircled Alvionna, enclosing her within a prison of water—the same ability Yuen had once used against Hex. At the same time, his body glimmered in blue light, a suit of water-forged armor wrapping tightly around him.
The audience could no longer see inside the watery domain. Headmaster Gareth quickly gave the order to send a drone into the vault. The live feed flickered to life on the giant screen above the arena.
What they saw stunned them.
Selion and his friends leaned forward, holding their breath. They had witnessed the Underwater Vault before, but this was unlike anything they remembered. Droplets gathered around Yuen, clustering at his hands and feet as if moving with a will of their own.
And then—
Beneath him, a majestic horse formed entirely from water rose up. In his hands, liquid coalesced into a weapon. A massive, radiant lance—like the ones used in the jousts of old. A weapon of knights, born of pure water, now gripped in Yuen's hands as the battlefield trembled.
Just then, Mia and Hex came rushing to join the others, their eyes fixed on the arena. Hex turned to Selion, his voice urgent:
— "What spell is he using?!"
Selion didn't answer. Hex glanced at him and saw his friend's lips parted, eyes wide and gleaming, but no sound came out.
— "Hey, Selion! What's going on?!" Hex pressed, this time almost shouting.
Selion drew in a shaky breath, his heart pounding in his chest. Words finally stumbled out, broken and trembling:
— "Yuen… h-he's using… the Underwater Vault!"
Hex frowned, disbelief flashing across his face.
— "That can't be right. The Underwater Vault has never looked like this. Are you sure you're not mistaken?"
Selion shook his head furiously, his voice firm now:
— "No. I'm certain! He shouted it himself: Underwater Vault—Second Form!"
Hex's eyes widened. He swallowed hard, then turned his gaze back to the screen. No longer was he merely watching—he was searching for answers.
And there, on the waves, stood Yuen—astride a horse of water, lance in hand, eyes burning with the fire of victory.