Fifnir

is a Pillar Baron of Behemoth's 34 Pillar Division.

Appearance
Nothing is known about his appearance as he never made an appearance. Though as a Pillar Baron, it can assume that he wears the same formal coats the other Pillar Barons wears.

Personality
Since he never made an appearance, Fifnir's personality is unknown, though it can be assumed that he is loyal to En as the Pillar Division were assisting En to ascend as the rightful heir to the throne.

Akumano Academy Arc
Fifnir's name is only seen by Mr. Takahashi's name roster when the Pillar Division were attending the Akumano Academy as students.

Powers & Abilities
Great Demonic Power: As a Pillar Baron, Fifnir is a powerful demon and has command over the lower-ranked demons.

Trivia

 * Fifnir's name is a corruption of the dwarf Fafnir, the strongest son of the dwarf king Hreiðmarr in Norse mythology.