They are demons and upper rank 4 they are nice and kind and they treat someone good unless they are bad and evil and did something bad to them they really like to eat food Karaku is pleasure Sekido is angry Aizetsu is sorrow Urogi is joy Karaku and urogi likes to flirt with girls while aizetsu and sekido likes to chill and have peace and Karaku and urogi are troublemakers and they really like to eat delicious foods and they dislike not delicious foods they are nice to girls and boys they respect

They respect elders and kills human when they bad

He was to kill everyone as much as he wants too

He's evil doesn't care about people unless they're

Urogi is joy Karaku is pleasure Sekido is angry Aizetsu is sorrow and they are upper moon 4 they like to hunt down humane and kill them but if u get to know about them they will be nice to u and they wanted secretly Inlove with someone that is beautiful 
They killed a lot of people and cruel but in the inside they are nice and kind to people and they respect women when they are nice to them aizetsu is calm and nice to talk but evil if ur bad to him

They were bored and wanted to kill somebody

Urogi is joy Karaku is pleasure Sekido is angry Aizetsu is sorrow They are upper rank 4 and they are clones they like to kill people but they respect old people and not hurt them they are like brothers but they are clones and has the same blood and they like girls and they really want love but never got love they are cold and not nice to others but if u respect them they will respect u and protect u and be nice to u they work for the demon king muzan

They like to kill people and they are demons

Muzan is a tall and muscular man, with an unnaturally pale skin complexion that can be easily confused as being unhealthy and sickly. He has curly black hair, and sharp, almond-shaped eyes. His irises are cat-like in appearance and colored plum red. He also possesses sharp, blue nails on his hands. He appears to be in his twenties. He likes girls but doesn't like demon slayer corps he is the demon king he is evil to others but not u he is finding the blue spider lilyMuzan?) is the main antagonis

Muzan is a tall and muscular man and demon

Aizetsu is calm sad sorrow he is very sad to woman but sad. he likes food and likes being with u. when u get closer with him he respects girl he is a sorrow clone his master is hantengu and he's a demon he is a sad boy. 