A sinister aquatic entity with a humanoid form, characterized by its chiseled features and deep azure skin, peers through the shadows with a pronounced furrowed brow. Its mouth is agape, revealing an array of needle-like teeth that glint menacingly in the muted underwater light. Encased in an ethereal underwater environment, the creature is bathed in a cinematic glow that highlights its formidable presence. Rendered in the realistic detail of Unreal Engine 4, subtle currents ripple through the water, casting dynamic patterns of light and shadow across its eerie and enigmatic visage.