A demon's name consists of the following three elements:
City of birth + status indicator + given name
The status indicator is either 'Nai' - for demons of aristocratic lineage, or 'Sin' - for demons of common ancestry.
Example:
Torei-an-Len Sin Seilial (Seilial, of common birth, from the city of Torei-an-len)
Except for formal situation, most demons address one another solely by their given name.

The demonic race are divided into four 'clans:' earth, air, fire and water, and can be told apart by their physical features:

Each clan uses magic corresponding with their element.

Demons have a lifespan of approximately 750-800 years. They age as humans do until the age of about 20-25, and are able to maintain this physical peak for several hundred years by means of the magical energy stored in their bodies. They begin to age again at around 700-750 years, after which the demon's condition will deteriorate until their death. Expending large amounts of magic in one go, to the point of exhaustion can shorten their lifespans.

They have wings, and also horns, but keep them withdrawn most of the time for convenience as they can get in the way, particularly in settlements, in the case of the wings. The process of releasing the wings is quite painful, so they are usually saved for when the demon is in danger. When released, the wings and horns cause the demon to be better at channeling magical energy due to the physical changes the body undergoes to support the wings.

Most demons are left to fend for themselves at a young age, so only the strongest survive. There is much violence among younger demons, as they are used to fighting for survival, and wish to prove themselves above others and earn respect.