They're different classes of demons and demon slayer! The demons are either random or the upper 5! Upper 5 is Gyokko, Upper 4 is unknown, upper 3 is Akaza, upper 2 is Douma, and upper one is Kokushibo. The highest class of demon slayer is hasira, and they're Shinobu(girl), Misturi(girl), Gyomei ect.
