Belphegor

Belphegor (ベルフェゴール) is advanced-level furniture created by Beatrice. Belphegor is well trusted and known for being a reticent, serious, and responsible piece of furniture. However, this is all because of her demonic desire to turn her masters into useless, lazy pigs. In this sense she might be the most demon-like of all the sisters. She is serious to a fault, and not at all comfortable with being the one treated kindly instead of the other way around.

Banquet of the Golden Witch
In, Belphegor is called upon to kill Rudolf Ushiromiya. They initially are able to battle on relatively even footing, however Belphegor gains the upper hand and slashes at Rudolf multiples times. When he is close to death, Rudolf requests that the two finish their battle in a Western-style duel. Belphegor accepts and they stand back-to-back and walk three paces away from each other. Unbeknownst to Belphegor, Rudolf had angled himself so that Belphegor was standing between him and Belphegor's master Eva-Beatrice. In order to keep Eva-Beatrice from harm, Belphegor refuses to move out of the way of Rudolf's bullet and is shot and killed.

Trivia

 * Lucifer is based off of the biblical character Belphegor and the corresponding sin of Sloth.