Filbert Grouse

Filbert Grouse is the bishop of a church. He is also Hazel's adoptive father and master. He is referred as the best slayer of the west.

In the Anime
The way Filbert died in the anime was sightly different from the manga. In the anime, Filbert was killed by Hazel while being possessed by Varuharu as a result of the curse set by him. Filbert's final moments, he told Hazel that he needs to let go of his hatred towards the youkais and find a person who will understand him. Hazel's memory about him killing his master were later sealed by the spirit together with Varuharu.