Portal of the Deep: Anime Portal in an Underwater Cave

An anime-style illustration of a glowing portal embedded in the rugged wall of an underwater cave. The portal is a perfect circle with a radiant frame etched with ancient runes, water swirling mysteriously inside. Surrounding rock formations drip stalactites; bioluminescent corals, seaweed, and jellyfish glow in electric blues, turquoise, and violet. Sunlight filters through the water, scattering into shimmering particles that drift around. A graceful anime-style adventurer with flowing hair, a sleek wetsuit, and bubbles trailing behind them swims toward the portal, their eyes reflecting its glow. The scene emphasizes depth with rippling water on the cave floor, distant walls, and a sense of awe and discovery. Rendered in vibrant anime style with cel shading, rich detail, and cinematic lighting. 16:9 composition.