The cavern was no longer a place of wonder; it had become a pit of nightmares. Hundreds of Deep-Sea Lurkers crawled along the walls, their jagged claws scraping against the stone with a sound that set Kaito's teeth on edge. Their pale red eyes were fixed on one thing: the glowing Altar.
"They are the scouts of the Abyss," Oro's voice boomed, his massive flippers churning the water. "If they breach the Altar, the ancient seal will break, and the darkness will consume this entire island. Stand your ground, Tide-Walker!"
Kaito's heart hammered against his ribs like a trapped bird. He looked at the silver whistle and then at the first wave of Lurkers leaping from the walls. They were fast—blurring shadows of teeth and claws.
"I can't... I don't know how to fight!" Kaito yelled, ducking as a creature lunged at his head.
"Don't fight them with your hands, Kaito! Fight them with the ocean!" Oro roared.
Kaito took a deep breath, forcing himself to remember the 'heartbeat' he had felt moments ago. He gripped his compass, which was now pulsing with a frantic, golden light. He pulled the whistle to his lips and blew a sharp, commanding note.
PHREEEEE!
The sound wasn't melodic this time. It was a war-cry.
Suddenly, the water of the lake responded. A massive wave rose behind Kaito, glowing with a fierce blue energy. It didn't just splash; it moved like a solid wall of liquid diamond.
"Now! Direct it!" Oro commanded.
Kaito thrust his hands forward. "Get back!"
The wave crashed into the first line of Lurkers, the sheer force of the magical water crushing them against the cavern walls. But more were coming. Kaito felt his energy draining—maintaining this much power was like trying to hold a galloping horse by its mane.
One Lurker managed to get behind him, its claws slashing across Kaito's shoulder. He cried out in pain, falling to one knee. The golden compass hit the ground, its light flickering.
"Kaito!" Oro called out, but he was busy swatting away larger creatures in the water.
Blood seeped through Kaito's shirt, but as the red droplets hit the stone floor near the Altar, something strange happened. The runes on the Altar flared to life. The whistle in his hand began to vibrate so hard it turned white-hot.
Kaito realized then that his father hadn't just left him a map; he had left him a legacy that required sacrifice. He stood up, ignored the stinging pain in his shoulder, and focused all his will on the water.
"This is my sea!" he roared.
He swung his arm in a wide arc. The water didn't just form a wave—it sharpened into a dozen spinning blades of high-pressure liquid.
"Tidal Blade!" Kaito screamed.
The water-blades flew through the air, slicing through the remaining Lurkers with surgical precision. One by one, the red eyes vanished into the dark, replaced by the calming blue glow of the lake.
Silence returned to the cave, broken only by Kaito's heavy breathing. He had won his first battle, but he knew the Abyss was only just beginning to wake.