Belphegor (ベルフェゴール, Berufegōru) is the 6th demon of the Reverse Kabbalah.
Belphegor resides in the body of Sect Crescent, along with Asmodeus. The demon is shown to have the power of invention and able to create multiple O-parts used by Zenom operatives, along with fake nuclei found by Jin. Sect states that using only Belphegor's power to create O-parts is very difficult and puts a large strain on his body, and it appears he has to use part of Asmodeus' power to create effectively. Using Belphegor, he was also able to turn Asmoedeus' darkness power into an attack, countered by Jio. It was revealed that Belphergor resided in his left eye since Sect left Ruby.