From Compendium of Worldly Lore
All warlocks harbor at least a grudging respect for the entities responsible for their powers. They are clearly beings of great mystical might, and thus worthy of regard. A rare few warlocks go beyond this attitude to actual reverence or worship of the fiendish, fey, or extraplanar powers that have made them far more than mortal. Such is the life of an eldritch disciple devoted to a deity who granted her the arcane talents of the warlock. Though her powers might take different forms, she knows that the source is the same.
Most eldritch disciples begin their careers as clerics, gaining reverence and insight into divine mysteries through that class before beginning to explore eldritch secrets. Both Corellon Larethian and Lolth commonly encourage their most devoted and charismatic worshipers to become eldritch disciples (typically through powerful agents such as eladrins or demons), but any chaotic or evil deity has room for such an individual. Occasionally, a warlock who "gets religion" finds his way into this class after dabbling as a cleric, but this instance is less common.
Role: Spell DPS
Characteristics: Warlocks and arcane casters don't get all the fun! This is a divine warlock theurge like class.
Source: Complete Mage
Game Rule Information
The Eldritch Disciple has the following game statistics.
Abilities: Charisma and Wisdom go hand in hand in this class in order to maximize the effectiveness of this class
Alignment: Any Nongood
Hit Die: d8
Starting Gold: N/A
Class Skills
The Eldritch Disciple's class skills are Bluff (Cha), Concentration (Con), Craft (Int), Diplomacy (Cha), Heal (Wis), Intimidate (Cha), Listen (Wis), Perform (Cha) Profession (Wis), Search (Int), Sense Motive (Wis), and Spot (Wis)
Skill Points at 1st Level: (2 + Int modifier) × 4
Skill Points at Each Additional Level: 2 + Int modifier
Class Features
All of the following are class features of the Eldritch Disciple.
Weapon and Armor Proficiency: A Eldritch Disciple is proficient with whatever they were already proficient with prior to taking levels in this class.
Invocations: At each level, you gain new invocations known and an increase in caster level as if you had also gained a level in an invocation-using class to which you belonged before adding the prestige class level. (This includes eldritch blast.) You do not, however, gain any other benefit a character of that class would have gained. If you had more than one invocation-using class before becoming an eldritch disciple, you must decide to which class to add each level for the purpose of determining caster level and invocations known.
Spellcasting: At each level beyond 1st, you gain new spells per day and an increase in caster level (and spells known, if applicable) as if you had also gained a level in a divine spellcasting class to which you belonged before adding the prestige class level. You do not, however, gain any other benefit a character of that class would have gained. If you had more than one divine spellcasting class before becoming an eldritch disciple, you must decide to which class to add each level for the purpose of determining spells per day, caster level, and spells known.
Gift of the Divine Patron Su: At 1st level, you gain a sacred gift of power from your divine patron (who is also the source of your cleric spells and, directly or indirectly, your warlock invocations). Choose one of the following abilities at 1st level, and another ability every three levels thereafter (4th, 7th, and 10th level). You can spend one of your turn/rebuke undead attempts as a swift action to activate the chosen power.
Corrupting Blast: In place of applying an eldritch essence invocation to your eldritch blast, you can change it into a corrupting blast. In addition to its normal effect, the blast applies a penalty on the target's next Will save equal to 1/2 your class level (minimum -1). If the target doesn't attempt a Will save before the end of your next turn, the effect fades.
Damage Reduction: You gain temporary damage reduction (overcome by cold iron) equal to 1/2 your class levels (minimum 1). This damage reduction stacks with the damage reduction granted by the warlock class. This effect lasts for a number of rounds equal to 3 + your Cha modifier (minimum 1 round).
Fearful Glare: You can render a single living creature within 30 feet of you shaken for 1 round (Will negates; DC 10 + class level + Cha modifier). This creature's HD can't exceed your character level.
Fiendish Resistance: You gain resistance to acid and fire equal to 10 + your class level. This resistance stacks with the energy resistance granted by the warlock class. This effect lasts for a number of rounds equal to 3 + your Cha modifier (minimum 1 round). Your deity must be evil for you to select this gift.
Healing Blast: In place of applying an eldritch essence invocation to your eldritch blast, you can change it into a healing blast. The blast heals living creatures instead of dealing damage to them (the damage healed is equal to the damage normally dealt). Against undead, the healing blast deals damage as normal; against constructs or objects, the healing blast has no effect. Your deity must be non-evil for you to select this gift.
Protective Aura: You surround yourself with a magic circle against evil centered on you. This effect lasts for a number of rounds equal to 3 + your Cha modifier (minimum 1 round). Your deity must be good for you to select this gift.
Strength of Will: You gain a bonus equal to 1/2 your class levels (minimum +1) on your next save to resist a mind-affecting spell or ability. This effect lasts for a number of rounds equal to 3 + your Cha modifier (minimum 1 round); if you haven't attempted an appropriate save in this time, the effect ends.
Wild Frenzy: You gain a +2 bonus on attack rolls and damage rolls with melee weapons and eldritch blasts, along with temporary hit points equal to your class level. This effect lasts for a number of rounds equal to 3 + your Cha modifier (minimum 1 round). Your deity must be chaotic for you to select this gift.
Turn/Rebuke Undead: Your eldritch disciple level stacks with your other class levels for the purposes of determining your ability to turn or rebuke undead.
Eldritch Spellweave Su: Beginning at 5th level, you can apply an eldritch essence invocation you know (other than greatreach blast or spellblast; see the eldritch theurge class features on page 57) to any divine spell that affects a target or that requires a melee or ranged touch attack. The spell's level must be at least as high as the level of the eldritch essence (for example, you can apply hellrime blast only to a spell of level 4th or higher). If the essence requires a saving throw, use the normal save DC for that essence. If the eldritch essence invocation changes the damage of the spell, it can be applied only to a spell that deals damage (you can't add brimstone blast to dimensional anchor, for example).
Using this ability increases the spell casting time to 1 full-round action. A spell that has a normal casting time of 1 full-round action or longer takes an extra full-round action to cast. If the spell has more than one target or allows more than one attack, you must choose one target to be affected by the invocation; all other targets take only the normal effect of the spell. You can use this ability a number of times per day equal to 3 + your Cha modifier (minimum 1).
Timeless Body: Beginning at 10th level, the divine power of your patron infuses you with eternal vigor. You no longer age.