Coven of the Dead

The loosely organized Coven of the Dead is a small religion, in the sense that nearly all of its members are active particpants in the religious structure - i.e. anyone professing to be a follower of this religion is likely either a witch or a hunter/warlock; there are no laypeople in the religion. That said, it is also quite a large religion in that everyone in the world is a believer, if not a follower - everybody dies eventually, and for the most part, we're all fans of the dead staying dead.
The Coven has two paths - that of Witch, the priest of the religion, or that of Hunter (also called Warlock). Both seek the same end - the preservation of Death - and hunters will always defer to the authority of a witch. Those that choose to join the Coven are not preoccupied with and do not promote Death, but seek to ensure that the power of Death is maintained and not corrupted. They are often feared and hated, and nearly always misunderstood.

Structure

The Coven is led by a council of seven witches, advised by the Warlock General, and is the only formal leadership the Coven has. Largely the religion is self-regulating: everyone knows their purpose, and witches are eminently practical folks. The Council of Seven, beyond making adminstrative decisions, are also the teachers of new witches. The Coven can be found in the city of Issuri, capitol of Issur, near to the university.
A witch's blessing is necessary to give the dead their proper rest, and without it, any being has the ability to return from the dead. Though few beings have the will to return themselves, without a witch's blessing at burial, they are subject to the will of others, such as necromancers or more powerful undead.

Culture

Witches are considered by most societies as a necessary evil. They can be found most anywhere - even the smallest villages will have a witch nearby, and generally one will be among a ship's crew. 
But because witches are always around when someone dies, they have unfairly become associated with extreme bad luck and feelings. In addition, they are somewhat preoccupied with their duties (burying the dead, dispossessing a place of undead, granting the undead their rest) and so may seem callous, even cold to those surviving the deceased. Comfort in bereavement is not their task - they let the living take care of the living.
Recognizing this, centuries ago, the Coven decided that it might be in their best interest to become useful to society in other ways than just hanging around waiting for folks to die. And so witches have become scholars of alchemy, and are considered the best folks to see if one needs a potion. This had the benefit of bringing in another source of income for the village witch, which was very appealing to the practical Coven.

Mythology & Lore

Witches are the chosen representatives of Death, and leaders of the Coven. Their philosophies reflect the permanence of Death in all things and their place as Death's guardians. As such, they pity the Undead with a great passion and have the ability to destroy them (i.e. grant them rest). Witches are also not cencerned about the afterlife, or anything beyond the immediate task at hand.

Cosmological Views

There are a number of good gods given respect and worship by the witches -- Larnir high amongst these, being deceased and having the decency to stay that way. Orcus is considered the ultimate evil, as he broke the law of Death and was the first to create the undead.

Priesthood

The priests are known as witches, and there is a military arm as well, known as hunters. "Witch" is not a gendered term - witches can be male, female, or neither. Witches tend to be folks who have seen the laws of Death flaunted up close and personal, and have felt the calling to do something about this. They can begin training with a witch in the area, but most will make their way to the Coven in Issur and train there. 
Hunter and Warlock are also not gendered terms - these are the enforcers and warriors of the religion and have among their membership people of every sex and various races. Hunters will always journey to the Coven to begin their studies - Hunters in the field are far too busy to take on an apprentice.

Granted Divine Powers

God	Patronage	Clerical Domains
Artura	Law, justice, mercy	Law, mysticism, inquisition, exorcism
Yeenoghu	Battle, war, bloodlust	Strength, war, domination
Zyghorra	Famine, plague, drought	Death, destruction, pestilence
Danna	Home, hearth, children	Good, healing, protection
Gladden	Village, festival, health, wine	Good, protection, community, creation
Merlyn	Magic	Divination, magic, mind, summoning
Larnir	Peace, commonsense, health	Good, healing, exorcism
Syrsha	Ruthlessness, treachery, deceit	Trickery, domination, evil
Tiamat	Ambition, violence, dominance	Knowledge, divination, domination
Mirronai	Dreams, visions, divination	Divination, madness, knowledge
Uller	Winter, archery, hunting	Travel, destruction, beastmaster
Drago	Luck, gamblers, helpless	Luck, travel, trickery, chaos
Vespertine	Moon, travel, night	Travel, celerity*

Sects

Ex-witches: Should a witch for some unknown reason ever create undead, or similarly fall from the path, she loses all status and special abilities, and better run like hell.
Hunters: Hunters (also called Warlocks) are the military of the Coven, and are pretty loosely organized, often taking direction from the witch they know best, or simply taking bounties on the undead. A hunter will always consider a witch his senior in the religion. Hunters are even less concerned with the living as the witches are; they are obsessive types who live simply to exterminate the undead. In game terms, they are the Hunters of the Dead (from the Defenders of the Faith text) with the following exceptions: d10 for hp, alignment is any. At 6th level, if the Hunter doesn't have the turning ability (from a different class) he gains the ability then, in place of the Extra turning ability. Hunters aren't as powerful as witches though in terms of this ability - they may only turn and dispel per the apporpriate tables.
Reavers: As if it weren't bad enough that any corpse not properly blessed has the potential to return, some idiots actively encourage this. The Reavers are a sect of witches that have lost their way, and believe, in essence, that when Orcus created the first zombie, he ushered in new age and effectively replaced death. In the Reaver's world, Orcus is Death, and the other gods are subordinate to him. Luckily the Reaver sect is limited to a few wackos and seekers after power. Witches and hunters will try to kill a reaver on sight. In game terms, the Reaver is the Master of Shrouds in DOF. The Reaver must pick new domains, and must rebuke rather than turn or destroy undead, but otherwise retains his priestly privileges (If a character wishes to start as a Reaver, he must start as a witch, and may change at 2nd.)
Gods and domains for reavers:

God	Patronage	Clerical Domains
Orcus	Undead, power, magic	Death, evil, magic
Yeenoghu	Battle, war, bloodlust	Strength, war, domination
Zyghorra	Famine, plague, drought	Death, destruction, pestilence
Syrsha	Ruthlessness, treachery, deceit	Trickery, domination, evil
Tiamat	Ambition, violence, dominance	Knowledge, divination, domination
Uller	Winter, archery, hunting	Travel, destruction, beastmaster
Vespertine	Moon, travel, night	Travel, celerity*

Type

Religious, Coven

Demonym

Witch

Game Notes:

Class Skills: as Cleric, with the exception that witches get alchemy instead of heal. Class features: Witches are proficient with simple bladed weapons and light armour. A witch casts spells as a cleric, and can choose two domains from any of the gods followed by the Coven. There are various alignments among the Coven, alignment being secondary again to the real aims of the religion. However, a witch can't cast spells from an opposed alignment domain.

1. Prime Requisite: Wisdom. Minimums: Wisdom 9, Strength 9, Constitution 12.
2. Instead of turning or rebuking undead, the witch will simply destroy them, as effectively as a cleric of the same level would turn.
3. At 1st level, they cast burial blessing spell at will.
4. At 3rd level, a witch gains a familiar with all the same attributes and effects as the sorcerer's familiar. However the witch can have more than one familiar, and can gain one every third level, up to a maximum of 4 familiars. All bonuses are cumulative, but so are all penalties if they should die. 
5. Witches gain the ability to brew potions with no XP penalty (free feat too) at 5th level.