The cover of the book is in the style of epic fantasy. A fragile but regal young goddess with long, flowing jet-black hair, dressed in a heavy, ornate snow-white cape with a hood and silver embroidery. She stands in front of a towering, powerful Demon Lord with dark eyes and dark robes. He looks protective and ferocious. The goddess holds a thin sword that radiates a soft purple-white-gold magical aura. The bright ruins of a Gothic castle in the background, purple fiery sparks and smoldering coals floating in the air. Cinematic lighting, hyper-realistic, highly detailed, dark and gloomy atmosphere, 8k, digital ArtStation-style illustration.