A colossal underwater coral reef cathedral at midday, massive natural coral arches forming gothic vaulted ceilings inhabited by schools of iridescent reef fish and sea turtles, exotic blue-ringed octopuses and leaf-like seahorses clinging to colorful coral spires, piercing sun rays slicing through crystal turquoise water creating volumetric light beams and dancing prismatic caustics on sandy floors, rendered with Unreal Engine 5 raytracing and PBR materials, reimagined as hand-painted Studio Ghibli animation with visible brushstrokes and watercolor texture, vivid coral pink and deep aquamarine gouache color palette, cinematic wide composition with strong atmospheric depth and majestic underwater sacred space atmosphere