Cinematic 8k wallpaper, colossal Cthulhu towering over a weathered lighthouse on a moss-covered rock, tumultuous sea churning around it, razor-sharp focus, designed to evoke megalophobia, exquisitely detailed 4k digital painting with subtle organic glow, photorealistic and movie-quality visuals, enveloped in a dark, moody atmosphere, dramatic light mixing with shadowy lumen reflections, atmospheric lighting casting an eerie ambiance, subsurface scattering revealing textures, hyperrealism with insane detail levels, like a highly realistic 64k UHD photo, captured as if through a DSLR lens, perfectly focused, achieved using Unreal Engine 5 and Octane render, 8k resolution.