An ethereal sea creature, resembling a human yet otherworldly, with sleek, angular features and a mesmerizing blue skin tone that shimmers against the ocean's depths. Its eyes are a deep, penetrating shade, underlined by a furrowed brow that suggests both wisdom and danger. Sharp, gleaming teeth are bared in a snarl from its slightly open mouth, hinting at its ferocious nature. Surrounding it is a mystical underwater realm, where shafts of light pierce the aquatic shadows, creating a cinematic and immersive scene that could be rendered in Unreal Engine 4 for a truly lifelike depiction.