First appearance: Battle 48

Age: 20

Height: 177cm

Weight: 69kg

Type: Sei

Type: Katsujin Ken

Martial Arts: Go no Sen

Kugenin Hibiki, commonly called Siegfried, was the former Fifth Fist of Ragnarok and is currently one of the leading captains of the Shinpaku Alliance. He is also called "The Immortal Composer" due to the fact that he composes music by using his battles as inspiration for his melodies.

Siegfried is a tall young man with very long grey-purple hair down to his waist with locks in the front down to his shoulders. He has a dark red coat with a hat with a feather on top to match it and dark boots and pants.

Siegfried has a tendency to hum or sing classical music during his fights and names his attacks after different music scores and compositions. He demonstrates great loyalty to whatever he associates music with and gets angry at those who make him lose track of his music. His talent in music, including the piano, violin, tambourine, and the bassoon, landed him a scholarship at a well-known school for music, and has even been consulted for musical advice on the bassoon.

This musical loyalty carries onto his defection from Ragnarok to Shinpaku Alliance, before which he stated his respect for Niijima and desired to hear the melody that the latter had "composed", and during which he comically explains in a song that he sat by the sea mourning the limit to his music until "Niijima-sama" came and played a flute-accordion, convincing him to join Shinpaku, the motive for which he states that he has heard a beautiful melody. His obsession with music carries further to his reconnaissance during the camping trip, when he strains from being unable to write music until he hears Tochumaru and his animal friends playing some music nearby.

With music as motivation for his loyalty, Siegfried demonstrates his loyalty to great, even extreme extents. He tried to swim across a river with three broken ribs to support Shinpaku in its final fight against Ragnarok, was willing to sacrifice his life for the rest of the Shinpaku members while being strangled by Li Raichi, and searched for it for three days nonstop during the D of D tournament, all for his "Dear Demon King" Niijima.

It is also revealed that Siegfried is very wealthy. He is solely responsible for providing all the funds necessary to reconstruct and renovate the Shinpaku Alliance's headquarters. Siegfried also seems to have some aptitude as a magician, being able to pull a bird out of his hat. He also appears to be quite an animal lover, as he claims to have 20 dogs and cats.