Create a highly realistic illustration of Thor's hammer, Mjölnir, in Scandinavian mythology style, shown in extreme close-up. The hammer should appear ancient and weathered, with intricate Nordic engravings on its surface, symbolizing power and protection. Lightning crackles around Mjölnir, illuminating the dark, stormy sky in the background, highlighting its connection to Thor. The texture of the hammer should be rugged, as if it's been through countless battles, but still unbreakable. The atmosphere should feel intense, with a mystical aura surrounding the hammer, emphasizing its legendary status in Norse mythology.