in my version Upper Moon 0 is a terrifying demon  

  
he has a very scary and sinister appearance with a hideous and frightening design  

  
he is very tall with long arms  

  
and he has a very savage and cruel personality with no sympathy for anyone at all  

  
his name is Kujou Kiriya   

  
and he is the most powerful demon in the upper moon rankings  

  
he is pure evil and a real monster  

  
his only goal is to kill all humans and destroy the demon slayer corps