Wallpaper portrait of a legendary ghostly knight, powerful and invincible, exuding an aura of brutality and epic strength, digital painting, dramatic and gloomy atmosphere, emotionally profound with volumetric lighting, intense and brooding dark tones creating a haunting impression on the psyche, high quality and high resolution, with careful attention to detail in anatomy and form, avoiding any text, name, signature, or watermark, conveying a sense of mystique and supernatural presence.