Rulers of the Underworld
The Source of All Evil
An essence which absorbs the one who has killed the previous Source. This essence has a vast amount of power and a strong will, completely taking over the one who it absorbed. the Source of All Evil has several demons which act as his right-hand man and/or assassin. He is advised by several oracles and Seers and rules over the Underworld. He sees himself as the most powerful demon in existence.
In order for the essence to access all of its powers, a ceremony must take place to crown the new demon as the putative ruler of demonkind. The coronation must be conducted by a Dark Priest and requires that the Source be touching the Grimoire.
Second in line to rule the Underworld is the Triad, a trio of demons who are the most feared and powerful collective of the demonic hierarchy. They have been responsible for a great amount of attacks on the Charmed Ones.
They first became known to the Charmed Ones in 2000, but were killed by Cole Turner, soon after. They then returned five years later as the demons Asmodeus, Baliel, and Candor who were vanquished by the Charmed Ones twice.
Also referred to as High-Level demons, these demons possess a great amount of power and have a high status in the Underworld. They are respected and feared by lower beings who usually offer their help in return for more power.
Most upper-level demons have an entry in the Halliwell's Book of Shadows, including information on their origin, Modus Operandi, powers, and method of vanquishing. The latter usually requires a potion made from their own flesh or a Power of Three spell.
Many upper-level demons owe allegiance to themselves and try to take over Underworld. The most notable demon for doing so would be Zankou. A demon so feared that even the Source of All Evil had imprisoned him into a magical barrier.
The Brotherhood of the Thorn
An elite society of powerful upper-level demons. An exclusive order of demonic mercenaries, the Brotherhood of the Thorn was formed by the Source of All Evil to gain a foothold in the mortal world by killing paragons of good and taking over businesses.
The Brotherhood answered directly to the Source, who in turn personally selected its members. Each member of the Brotherhood was given a unique athame, which could be recognized by other demons as belonging to a member of the Brotherhood. The members take a blood oath, a lifelong pledge of loyalty.
The Four Horsemen of the Apocalypse
Empowered directly by the Source of All Evil himself, the Four Horsemen of the Apocalypse are responsible for starting the apocalypse. No spell or potion can destroy them, only the Source is able to kill them and does so when they fail their mission. They are then replaced by another set of horsemen. Their symbol is the Omega.
The Ordo Malorum
Upper-level demonic generals who lead the war against the forces of good. Members of the Ordo Malorum were once in the possession of a genie, handing them over to each other after they had gotten their three wishes.
Upper-level demons who were born with a human half, usually so they could be incorporated into the mortal world as business men. These demons possess a soul and are more susceptible to becoming good. Notable examples are: Belthazor/Cole Turner, Sykes, Sirk, and the Manticore Baby.
Their human parent is usually killed by its demonic parent once the baby is born.
Also referred to as Base-Level demons, these demons are on the penultimate rank of the Demonic Hierarchy. Their small amount of power and often little intelligence makes them easy prey for the Charmed Ones and upper-level demons.
They are often hired to do the dirty work of upper-level demons in return for more power. Though some of them prefer to act alone, such as the Water Demon.
Only a select few of low-level demons have earned an entry in the Halliwell's Book of Shadows, mostly because they were large pests instead of serious threats.
The Bottom of the Demonic Hierarchy
At the bottom of the Demonic Hierarchy are those demons banished by the Source of All Evil or the Triad and warlocks. Although they are not demonic, Warlocks are listed on the lowest rank of the Demonic Hierarchy. They are considered to be such a weak form of evil that they are even forbidden to kill (or even try to kill) a demon and absorb their powers by demonic law.
Demons who were banished by the Source had betrayed him by either trying to kill him or take over the Underworld. They were banished into the mortal world and were not allowed to enter the Underworld again. Such demons were: vampires, Kurzon, and Xar (who was banished by the Triad). They are considered to be the vermin of all demonic beings.
The following beings have do not have any particular rank and are seen as a neutral party.
A council made up of two Elders and two demons, the Tribunal were created to monitor magic. They act as a neutral party to anyone, good or evil, and stand above anyone else. They are believed to be powerful beyond comprehension but do not act unless they need to.
Demons who stand by and advise the most powerful demons, usually those who rule the Underworld. They are often Seers, Oracles or Dark Priestesses and keep themselves in the background, acting only when needed. They are far more powerful than they let seem.