A colossal sky-fortress keep floating among eternal storm clouds, massive ancient stone towers wrapped in lightning-struck metal chains and swirling cyclone currents, weathered battlements manned by storm-worn sky pirates with wind-whipped cloaks, dozens of elemental storm sprites with electric blue light swirling like living thunder, dramatic lightning backlighting with towering cumulonimbus silhouettes and falling rain curtain, deep storm gray electric blue metallic silver ancient stone white and cloud white color palette, Painterly digital art style, concept art for video game, aerial fortress composition with sky kingdom lore details