"Belphegor is a major character in the popular Japanese manga, ""The Devil King’s Sonata."" She is a powerful demon who is ferocious in battle but also possesses a calm and cunning intellect. Her name appears several times throughout the series, as she is a key player in the ongoing struggle between good and evil.

Belphegor is often depicted as having long, blonde hair and yellow eyes. She wears a black outfit with a high collar, which accentuates her regal bearing. Her personality is complex - she can be both ruthless and compassionate, depending on the situation. Belphegor is a formidable opponent, with a mastery of various weapons such as swords, daggers, and whips.

One of the defining characteristics of Belphegor is her loyalty to the Demon King. As one of the King's most trusted advisors, she works tirelessly to ensure that his will is carried out. However, this loyalty is not blind, and Belphegor is not afraid to speak out when she disagrees with the King's decisions. She also has a deep respect for the other demons that serve under the King, including her fellow commanders.

Throughout the series, Belphegor goes through significant character development. She is initially depicted as an emotionless and cruel demon, but as the story progresses, she begins to show more compassion towards her enemies. This is particularly evident in her interactions with the protagonist, a human who seeks to defeat the Demon King. While she remains committed to her role as a demon commander, she begins to question whether the King's rule is truly just.

In summary, Belphegor is a complex and intriguing character in ""The Devil King’s Sonata."" Her personality, loyalty, and fighting skills make her a formidable opponent, but her compassion and developing moral code make her a sympathetic figure as well. Her name appears frequently throughout the manga, as she plays a major role in the ongoing conflict between good and evil."