Avoid any imagery that is cartoonish, overly simplistic, or lacks depth and texture. Do not include elements that are out of place in a dark fantasy setting, such as modern technology, contemporary clothing, or anachronistic architecture. Refrain from using a bright, cheerful color palette that would contradict the story's atmosphere of mystery and intrigue. Stay away from depicting Phillip or the castle in a way that feels static or lifeless; the cover should evoke a sense of movement and emotional depth. Ensure that the unifying element for the series is not obscured or minimally represented; it should be clearly visible and integral to the cover's composition. Exclude any portrayal of graphic violence, explicit content, or anything that would misrepresent the story's focus on themes of diplomacy, love, and self-discovery.