Long spiky black hair thats tied into a ponytail.
Upper-moon one, he is the strongest of all the demons, except muzan the demon king.
He uses his katana to fight.
He uses breathing-styles (breathing styles are a type of magic that can only be used on katanas)
He has six eyes.
He has red scleras and yellow eyes.
The words "Upper Moon 1" are imprinted in his yellow eyes.
He uses moon-breathing
He is a demon
He has a purple kimono
He can regenerate body-parts and wounds/injuries very fast.