- I am not the only one! I am one of millions! In places you can't even imagine! In forms you would never believe! We are hell on this earth! You'll never be safe! And you'll never be free!"
- —The warlock Jeremy to the Charmed Ones on all sorts ofevil beings[src]
Demons are a race of magical beings motivated by Evil. They seek out to kill innocents and the forces of Good. Demons are unable to feel emotions and possess no soul or conscience. Almost all demons are immortal, and in some occasions, however, a demon can become good and desire to live a mortal life.
For centuries they have been ruled by the Source of All Evil, who claimed to be the most powerful of all demons. Most demons live in the Underworld or the mortal world, depending on what goal they wish to achieve or how they influence the mortal world. When exiled, a demon is not allowed to live in or enter the Underworld which is punishable by death.
Demons are said to come in every shape and form. And while that is true, most demons seem to have a human appearance, either by nature or with magical help. It is also possible for demon to have an amorphous body instead of physical form.
There are many powers, some which are generally possessed by many demons, others which are unique to their owners.
However, demons can collect various powers by killing other demons or stealing them, making them much more powerful. Demons like Zankou and Zahn in particular were able to do so. Zahn was able to up his rank from low- to upper-level over the centuries.Lower-level demons generally have basic demonic powers that are of not much use. Upper-level demons generally possess the ability to shimmer and throw energy balls, and depending on their status can throw Fireballs as well. The Source of All Evil was the one of the only demons to be able to teleport with flames, a way to show of his high status and leadership.
Most demons are not able to cast spells and brew potions but are vulnerable to them. Upper-level demons might have learned to master these abilities or at least grow strong enough to withstand them or become immune. Members of the Ordo Malorum for example are immune to the powers of witches.