Tharizdun (Dark God, He of Eternal Darkness, The Evil One)
Setting: Greyhawk
Sources: Various Sources, Codex of Greyhawk Website, WG4: Forgotten Temple of Tharizdun, The Powers of Greyhawk (Found online at one of the many Greyhawk Sites), Gord’s Greyhawk Books
Notes: I took a few liberties to flesh out the priesthood, but most of this is based on the canonical sources and The Powers of Greyhawk (no clue who wrote this, but it’s based on canon material also).
Last Updated: January 7, 2001

Tharizdun is known as the Master of Malevolence, the Darkest, the Ultimate One of Nullity. The Dark God is the epitome of evil and he would unite all evil, had he not been entrapped by Good Deities of Greyhawk eons ago. They enmeshed him in a cocoon of his own power, but he could still act in a limited way. He lies wrapped in ebon slumber, awaiting the joining of the Theorparts. If they are joined, he will be released and the Upper and middle planes will ally against evil.

Tharizdun is associated with loss of strength and sanity, exhaustion and cold, fatigue, mind-bending illusions, depression, catatonia, and paralysis.  Legend says that Tharizdun is banished and imprisoned in some unknown demi-plane by the allied Good and Neutral Deities eons ago. They enmeshed him in a cocoon of his own power, but he could still act in a limited way.  Rumor has it that the Suloise consorted with Tharizdun to bring about the Invoked Devastation in the Suel-Baklunish Wars.  The Dark One perhaps even had a hand in the more recent cataclysm that overtook Oerth.  Perhaps the Suel history is why the Scarlet Brotherhood is said to revere Tharizdun and to seek his release.

Release of Tharizdun is rumored to be through the use of three Theoparts.  Each Theopart is an artifact of evil of immense power and represents one each of Law, Neutrality, and Chaos.  Rumors have it that individually they possess the power to summon demons and turn back time.  Together, they form the Tripartite Artifact of All Evil, and in the hands of a being of divine ancestry, they possess the ability to resurrect Tharizdun from his banishment.

It is thought that the Chaotic Evil Theopart (The Initiator) is held by the Scarlet Brotherhood.  The Neutral Evil Theopart(The Awakener - The Vitalizer - The Arouser) is rumored kept in a pyramid in the Suss forest and the Lawful Evil Theopart (The Unbinder - The Cone of the Magi) supposedly lies in the Suloise metropolis now known as the Forgotten City. Conflicting rumors place one or more of the Theoparts below the ruins of Greyhawk Castle.  As insurance against The Evil One's release, all parts can only be retrieved by mortals.  No matter who holds them, they will be corrupted and lost to an evil power.

Tharizdun can take as many forms as there is evil in the world.  One of his common forms is that of a purple cloud. The cloud has dark eyes, emitting an amethyst light, purple, black, lipless mouth with many teeth, tusks, and fangs, that are all very large, and a hairless black hide full of blemishes.  Another form is that of a six foot, six inches tall comely human with fair skin, gold hair, fangs, and an incredibly deep sonorous voice.

Worship of Tharizdun takes place in unknown subterranean temples of chill, darkness, and insanity.  Such places are highly secret, and many are lost and ruined.  Litanies of this Power are hideous in the extreme.  Most folk feel that the less they know about the Dark God, the better they like it.  Even mention of his dread name is held to be a danger.  In lands controlled by Iuz, this is even more so, as return of The Evil One would mean an end to the demigod.

Yeth Hounds
Three variations of Yeth hounds are the creations of Tharizdun, each one bearing the head of a different malevolent creature. These variants are the same as the Yeth Hounds in the Monster Manual pg 188 except for the following changes:
Mephisto – a devil-headed yeth hound: SR 16, Petrifying gaze (DC10, Fortitude) (Su), 4d10+4 HD, CR5, Lawful Evil
Thrax - a bugbear-headed yeth hound: SR12, Summon Bugbears (3-12) 75% (Sp), 5d10+5 HD, CR5, Neutral Evil
Graz - a demon headed yeth hound: SR14, Summon Hell Hound 65% (Sp), 4d10+2, CR5, Chaotic Evil

Tharizdun's Priests – Herald of Darkness Prestige Class

The sole duty of this priesthood is to free Tharizdun from his prison.  They sacrifice all to this end.  The extent and location of the priesthood is unknown, though it is thought to be extinct.  The priests of Tharizdun wear a Holy symbol with an inverted Ziggurat to symbolize his imprisonment, though often their holy symbol is hidden to avoid notice.

Despised by good deities, feared by other evil deities, and seen as a threat to those of neutral inclination, it is no surprise that priests of Tharizdun have become master’s of trickery.  They often disguise themselves as mages and priests of other faiths to hide their true nature while gaining power and prestige – and even spells from other evil deities.  Many of Tharizdun’s priests have resorted to wizardry to further their cause, and even more dabble in Alchemy to create horrific poisons.

Heralds of Darkness wear black robes and carry a holy symbol with inverted Ziggurat when conducting rituals and services in the name of Tharizdun.  While in a place of worship to Tharizdun. Heralds of Darkness are referred to by named rank (in increasing order): Herald of Darkness, Herald of Malevolence, Herald of Evil, Harbinger of Darkness, Harbinger of Malevolence, Harbinger of Evil, Master of Darkness, Master of Malevolence, Master of Evil, One of Eternal Darkness, One of Malevolence, One of Evil, One of Nullity.

Class Level	Base Attack Bonus	Fortitude Save	Reflex Save	Will Save	Special	Title	
1	+1	+2	+0	+2	Cold of the Void	Herald of Darkness	
2	+2	+3	+0	+3	Dark Blessing	Herald of Malevolence	
3	+3	+3	+1	+3	Undetectable alignment	Herald of Evil	
4	+4	+4	+1	+4	Dark Pact	Harbinger of Darkness	
5	+5	+4	+1	+4	Suggestion	Harbinger of Malevolence	
6	+6	+5	+2	+5	Dark Gift	Harbinger of Evil	
7	+6//+1	+5	+2	+5	Mute Evil,
Undetectable alignment	Master of Darkness	
8	+7	+6	+2	+6	Darkness Bound,
Undetectable alignment	Master of Malevolence	
9	+7/+1	+6	+3	+6	Otiluke's freezing sphere	Master of Evil	
10	+8	+7	+3	+7	Mute Evil, Suggestion 	One of Eternal Darkness	
11	+8/+1	+7	+4	+7	Darkness Bound,
Suggestion	One of Malevolence	
12	+9	+8	+4	+8	Irresistible Void, Otiluke's freezing sphere	One of Evil	
13	+9/+1	+8	+5	+8	Power of the Void,
Otiluke's freezing sphere
One of Nullity	One of Nullity	

Hit Dice: 1d8
Requirements:
	Ability Score: Wis 15
Alignment: Any evil
Knowledge: (arcane): 4 ranks
Knowledge (religion): 2 ranks
Disguise: 2 ranks
Perform: 2 ranks
Special: To become a Herald of Darkness, the character must have committed an act of utter evil, such as slaying an unknown innocent whilst family members watched or poisoning the only food source of a town.

Class Skills: Alchemy (Int), Concentration (Con), Diplomacy (Cha), Disguise (Cha), Knowledge (arcane) (Int), Knowledge (religion) (Int), Perform (Cha), Profession (Wis), Scry (Int, exclusive skill), and Spellcraft (Int)
Skill Points at Each Level: 2 + Int modifier

Class Features:
Armor & Weapon Proficiencies: Proficient in all Simple Weapons and all types of armor and with shields.
Bonus Languages: Abyssal and Infernal
Deity Domains, Domain Spells: Evil, Water (Cold), Trickery, Destruction
Spells: Heralds of Darkness cast spells as a cleric.  To determine spell level, add the levels of Cleric and of Herald of Darkness.
Spell Restrictions: 
(special note: priests of Tharizdun may not currently use priest spells above 2nd level due to the Power's imprisonment)
Lesser Access (3rd Level & Below): Protection
Forbidden: Good, Healing, Sun
Command Undead: A Herald of Darkness has the supernatural ability to command and rebuke undead as a cleric of the same level.
Cold of the Void: a Herald of Darkness of 1st  level or higher may use all cold-based wizard spells as priest spells of same level.  
Dark Blessing: a Herald of Darkness of 2nd level or higher applies his Charisma modifier (if positive) as a bonus to all saving throws.
Undetectable alignment: Once a day, a Herald of Darkness of 3rd level or higher gains the ability to use the spell Undetectable alignment as a supernatural ability (Clr2)
Dark Pact: a Herald of Darkness of 4th  level or higher may add any levels of Cleric to his levels of Herald of Darkness to determine his level of ability to command or rebuke undead.
Suggestion: Once a day, a Herald of Darkness of 5th level or higher gains the ability to use the spell Suggestion with accompanying visual illusion if appropriate (Wiz3)
Dark Gift: a Herald of Darkness of 6th  level or higher may add any levels in Herald of Darkness level to any Cleric levels for purpose of determining Cleric and Herald of Darkness spell level.  Further, the Dark Gift allows the cleric to summon 1d3 Yeth Hounds as though casting a summon monster spell once per day per 3 levels of Herald of Darkness.  The cleric has a d% chance of success equal to (Wisdom modifier + Herald of Darkness level) x 5 and the Yeth Hounds remain for a number of hours equal to the Herald of Darkness level.  Further, there is a 50% chance that one of the Yeth Hounds will be of the Tharizdun variations (see above under the heading Yeth hound.)  The Tharizdun variant will correspond to the alignment of the Herald of Darkness.
Mute Evil, Undetectable alignment: a Herald of Darkness of 7th  level or higher gains the Silent Spell feat.  This one is for use with Undetectable alignment ability.  Further, the Herald of Darkness gains the Undetectable alignment ability twice a day.
Darkness Bound, Undetectable alignment: a Herald of Darkness of 8th  level or higher gains the Still Spell feat.  This one is for use with Undetectable alignment ability.  Further, the Herald of Darkness gains the Undetectable alignment ability three times a day.
Otiluke's freezing sphere: Once a day, a Herald of Darkness of 9th level or higher gains the ability to use the spell Otiluke's freezing sphere (Wiz6)
Mute Evil, Suggestion: a Herald of Darkness of 10th  level or higher gains the Silent Spell feat.  This one is for use with Suggestion ability.  Further, the Herald of Darkness gains the Suggestion ability twice a day.
Darkness Bound, Suggestion: a Herald of Darkness of 11th  level or higher gains the Still Spell feat.  This one is for use with Suggestion ability.  Further, the Herald of Darkness gains the Suggestion ability three times a day.
Irresistible Void, Otiluke's freezing sphere: a Herald of Darkness of 12th  level or higher gains the Spell Focus feat.  This one is for use with Otiluke's freezing sphere ability.  Further, the Herald of Darkness gains the Otiluke's freezing sphere ability twice a day.
Power of the Void, Otiluke's freezing sphere: a Herald of Darkness of 13th  level gains the Maximize Spell feat.  This one is for use with Otiluke's freezing sphere ability.  Further, the Herald of Darkness gains the Otiluke's freezing sphere ability three times a day.
One of Nullity: a Herald of Darkness of 13th level gains the ability to effectively nullify his existence on the Prime Material Plane.  Once per year and at the expense of 13,000 XP, the Herald of Darkness may call upon the powers of Tharizdun’s prison to place himself in Temporal Stasis (Wiz7) and under the effects of an Ethereal Jaunt as per the spells of the same name except that the duration is of the Herald of Darkness’s choosing, up to 1 year per level.  A Herald of Darkness may not use this ability if the XP loss would cause him to loose a level in Herald of Darkness.