Create an illustration that captures a moonlit night in a medieval city with gothic architecture, including spires and rooftops. Place a sinister horned creature wielding a sword perched on a rooftop, standing guard over two trembling figures. Highlight the intricate details of the architecture and the creature to emphasize a feeling of darkness and mystery. Use dramatic lighting to evoke a sense of fantasy and horror, illuminated by the light of the moon. Ensure the atmosphere conveys the tension and chilling presence of the scene, portraying a dark, otherworldly tale, Illustration of a moonlit night in a medieval city with a horned creature holding a sword. Sinister atmosphere with two figures on rooftop. Gothic spires in the background create a mysterious backdrop with intricate linework and dramatic shadows