Flute Demon

The Flute Demon was a Demon exclusive to the Special One-Shot who desired to join the Twelve Kizuki. He was responsible for the deaths of a small group of Demon Slayers and innocent civilians.

Appearance
The Flute Demon takes the appearance of a very elderly man with wrinkly skin, and incredibly long black downward-slanted eyebrows. He has long slanted eyes with black scleras similar to the Serpent Demon with the traditional fangs of a demon.

His attire consisted of a flower-patterned kataginu-sleeveless robe tied to one side by a white ribbon and long white kimono with a thick black frame at the cuffs. He has long black sashibuki/nu-bakama pants similar in appearance to the Demon Slayer Corps members with geta shoes. As well as this, he wears a black Japanese saggy cap with a tassel at the end.

Personality
Not much can be said from the Flute Demon's personality other than he has been shown to be fairly arrogant when he believed that Kyojuro alone as reinforcements wouldn't be enough to defeat him. Along with this, he also has the incredibly sadistic and homicidal perspective of a demon as he only focused on his victims going to "hell" as well as him having a joyful attitude on horrible situations such as him sucking out internal organs of multiple children and murdering multiple Demon Slayers in front of them.

Special One-Shot
The Flute Demon sits atop a rock, admiring the corpses of his victims. Kyojuro Rengoku arrives at the scene, and the Flute Demon smiles at his appearance, confident that Kyojuro alone will not be able to defeat him. The Flute Demon taunts Kyojuro with tales of his previous killings, reveling in the misery he has caused. Kyojuro rushes forward, determined to put an end to the demon's reign of terror. The Flute Demon dodges Kyojuro's opening attack, and plays his flute, causing Kyojuro to cover his ears in discomfort. The Flute Demon taunts Kyojuro, claiming that he will meet his end at his hands, even calling him a "poor soul". Kyojuro thinks back to the many people who have risked their lives for the sake of others, and realizes that he must rise to the challenge in order to protect those who can't protect themselves. He removes his hands from his ears and continues to fight, dispatching the wolves that the Flute Demon sends his way, and beheading the demon. The Flute Demon is shocked by Kyojuro's power, wondering how Kyojuro was able to kill him. Kyojuro, a smile on his face, reveals that he tore out his eardrums to avoid falling prey to the Flute Demon's mind games. The Flute Demon, realizing his defeat, screams at Kyojuro, claiming that he was destined to become one of the Twelve Kizuki. Kyojuro, satisfied with his victory, watches as the Flute Demon dies screaming.

Overall Abilities
Due to him being able to easily evade Kyojuro's first attack as well as him killing nine Demon Slayers, it is inferred that he is incredibly powerful compared to the average demon. In addition, due to him stating that he would soon join the Twelve Kizuki, it can be assumed that his strength is near equal to that of a Lower Rank member.

Blood Demon Art
Flute Spells: The Flute Demon's main ability is to conjure a special flute that when played, enacts various effects.
 * Nervous System Disruption: When his flute is played, it disrupts the nervous system of his opponents (if they try move one of their feet, their head will move instead, if they attempt to move one of their hands, their feet will move, etc.), thus making it nearly impossible to accurately move.
 * Wolf Manipulation: This demon can also use his flute to summon 2 black wolves and command them to kill his opponents. It is unsure whether he can summon more than 2 demonic wolves.

Quotes

 * (To Kyojuro Rengoku) "My dogs will devour you... as you wriggle like a filthy worm!"
 * (Last sentence before death) "No!! I was going to join the Twelve Kizu..."