The Demons is a race of supernatural beings that the Order fights against and that Chrono belongs to. Monsters who are mostly hostile towards humans, though they do seem to have a violent nature, are not completely evil. They are born with a material body, they are not immortal and they can be either male or female, they never grow old, and have extraordinary powers that are based on the energy of the Astral Line. Their origins and goals differ depending on whether you're following the manga or the anime, but both versions seem to be filled with proud warriors that look down upon humans and consider them tools at best. All demons are born from one mother, Pandaemonium, the demon queen.
In the manga Demons have their own society, an oppressive community similar to a beehive, where everyone has a rank according to their power level.