A touching underwater scene showing the teenage merman idol discovering a group of terrified castle residents huddled together in a corner of the sunken castle ruins, the merman idol swimming toward them with gentle concern and compassion, his expression soft and reassuring, his beautiful androgynous face showing kindness and warmth, his long flowing marine blue hair drifting weightlessly around him, his fin-like ears with soft bioluminescent edges glowing with gentle cyan light. He wears his elaborate sea green velvet tailcoat with extensive raden mother-of-pearl inlay, silver filigree, crimson rose embroidery, pearl-adorned choker, pearl necklaces, pearl shoulder ornaments, pearl buttons, pearl cuffs, pearl sash, pearl anklets, pearl earrings, pearl hair ornaments, ruffled white silk shirt with pearl-pin cravat, sea green leather pants, knee-high boots with silver and pearl decorations. His pearl-adorned hands are extended toward the cowering residents in a calming gesture, his eyes wide with gentle understanding. The castle residents shown include a frightened chambermaid clutching her apron, a terrified kitchen boy holding a wooden spoon defensively, a shaking elderly advisor with disheveled white robes, a crying young noblewoman in torn fancy dress, and two trembling guards with broken spears, all huddled together against a crumbling castle wall covered in bioluminescent anemones, their faces showing shock and fear of the underwater environment, bubbles escaping their mouths as they struggle to understand what happened, their eyes wide with confusion and terror. The setting shows the interior of the sunken castle with crumbling stone walls, broken windows with golden light streaming through, fallen chandeliers with glowing crystals, floating furniture and tapestries, scattered golden coins and jewels from overturned treasure chests, ancient stone pillars entwined with bioluminescent sea anemones in pink,purple, and cyan, schools of small fish swimming through the ruins, translucent jellyfish drifting like living lanterns, golden volumetric god rays filtering through the water creating a cathedral-like atmosphere, thousands of tiny glowing particles floating like underwater stars, soft coral formations in crimson and purple. The atmosphere is tense yet hopeful, showing the moment of discovery and the beginning of rescue, the merman idol's compassion reaching out to the terrified victims of the castle's sinking. MAGICAL FANTASTICAL UNDERWATER LIGHTING with shimmering volumetric god rays, prismatic light refractions, cascading golden rays, rendered in a high-fidelity, detailed anime aesthetic with glossy delicacy and cinematic depth.