A mystical narwhal gliding through ethereal Arctic waters at twilight, National Geographic quality underwater wildlife art, legendary spiral tusk piercing the crystalline depth, sleek mottled gray body with distinctive markings, surrounding aurora-like bioluminescent plankton creating celestial constellations, mood of mythical Arctic wonder and ancient sea creature magic, deep indigo and soft cyan palette with ghostly pale light, dramatic close-up composition from beside emphasizing the narwhal's unicorn-like tusk against the mysterious polar depths, shallow depth of field with distant ice formations and floating particles fading into dark Arctic water, cinematic composition