Here are the Duke's member.

The Duke: Have a scary face that make people think he an evil person. He personally is a hard working person who is quiet sensitive. He is in charge of the finance in the kingdom. He understand he has a scary face and even sometime scare himself when going to the bathroom at night when looking in the mirror.

The Duke wife: A person that look younger then her actual age while having a pet monster spider. She herself is quiet a beauty and love her husband and children very much and not afraid to said it out loud. She love cooking especially for her husband and her pet spider. She however don't see her husband face as scary and see as handsome and so don't understand why people are afraid of her husband. She also have habit of see someone or someone clothing and stated some type of food ingredients out lot because of her hobby on cooking but people don't know that and if heard what she say will think she [duke wife] is trying to cook them for her pet spider.

Duke Son: Had a face that look like he scheming something evil behind everyone back. He himself understand why everyone in his family have bad rumor including himself and he feel sad about it. Because of his face he lack (human) friend expect his pet snake. He work in the magic guild.

Duke daughter: As a reader, the best way to describe her in two word are "muscle brain". A beauty that is a "muscle brain" that on the dumb side. She is a female knight who is quiet scary strong, who can cut a monster in two that known for it strong armor and defense. She being called eccentric by both her mother and brother for wearing a full metal armor with helm like nothing. As a reader we would describe her as muscle brain (on the dumb side), and a Female Otaku (because of her interest). She totally don't understand why she and her family are scary by other people pov.