God-blooded is a template from the Monster Manual V and gives a number of variations based on the deity.
This is my go at the deity of the illithids...
"Ilsensine-Blooded" is an acquired template that can be added to any illithid, half-illithid, or urophion. An illithid gains the template by feeding on the brain of a creature with an intelligence score of 30 or higher. It dedicates the knowledge within directly to Ilsensine. If having learnt something interesting from the knowledge within the brain, Ilsensine will use a spark of its own psychometabolic power to infuse the feeder.
A creature that gains this template begins to give off an emerald glow. Thousands of tiny, twitching tentacles sprout all about its head, which noticably swells in size.
An ilsensine-blooded creature has all the special attacks of the base creature, plus the following special attacks.
Superior Mind Blast (Su):
The DC of an ilsensine-blooded creature's Mind Blast ability increases by +2, and it adds its Intelligence modifier to the number of rounds they remain stunned.
If the ilsensine blooded creature does not already have the mind blast ability it gains the ability as the mindflayer.
Unholy Mind (Su):
Anyone who attempts to use a mind-affecting power, spell or other ability on the ilsensine-blooded must make a save or be affected by it's mind blast ability. The blooded creature does not have to be aware of the mental intruder, nor is it limited by distance or direction.
An ilsensine-blooded creature has all the special qualities of the base creature, plus the following special qualities.
An ilsensine-blooded creature can take a free action to gain the damage reduction 10/- from the mingling of divine blood with its material form. The creature can supress this ability with another free action. Once the damage reduction has prevented 40 points of damage, the creature loses all benefit of the template, including this ability, except when otherwise noted.
Food For Thought (Su)
: An ilsensine-blooded creature that eats a brain gains the answer to a number of questions from it equal to the blooded creature's intelligence modifier as the Mind Probe power. If the brain comes from a psionic character the ilsensine-blooded creature gains half its unused power points (round down). This cannot increase the number of power points past the blooded's full natural total.
Characters who have ranks in Knowledge (religion) can learn more about ilsensine-blooded creatures. When a character makes a successful skill check, the following lore is revealed, including the information from lower DCs.
15 Ilsensine-blooded creatures are divine champions infused with the essence of Ilsensine. The god's blood within them makes them incredibly durable, but if they are sorely wounded, the god's power fades from them.
20 An ilsensine-blooded creature's mind is particular hostile against mental intrusion and will lash out violently.
25 An ilsensine-blooded's mind blast ability is more difficult to save against and victims are stunned for greater lengths of time than normal.
30 An illsensine-blooded creature gains knowledge and power from every brain it eats.
Sample Ilsensine-Blooded Creature
Ilsensine-Blooded Mindflayer Cleric 3/Psychic Theurge
Hit Dice: 8d8+8 + 3d8+3 + 4d4+4 (74 hp)
Speed: 30 ft. (6 squares)
Armor Class: 15 (+2 dex, +3 natural), touch 12, flat-footed 13
Base Attack/Grapple: +10/+15
Attack: Tentacle +11 melee (1d4+1)
Full Attack: 4 tentacles +11 melee (1d4+1)
Space/Reach: 5 ft./5 ft.
Special Attacks: Extract, improved grab, psionic powers, rebuke undead, spells, superior mind blast, unholy mind
Special Qualities: Divine endurance, food for thought, power resistance 25, telepathy 100 ft.
Saves: Fort +7, Ref +9, Will +17
Abilities: Str 12, Dex 14, Con 12, Int 20, Wis 18, Cha 17
Skills: Bluff +18, Concentration +16, Diplomacy +5, Disguise +4 (+6 acting), Hide +12, Knowledge (psionics) +17, Knowledge (religion), +15, Listen +13, Move Silently +12, Psicraft +9, Sense Motive +15, Spot +13, Use Magic Devide +8, Use Psionic Device +9
Feats: Combat Manifestation, Improved Initiative, Improved Grapple, Insightful Reflexes
, Practised Manifester
, Weapon Finesse
Challenge Rating: 16
Treasure: Double standard
Alignment: Lawful evil
Level Adjustment: +8
Tlusutin is a truly horrifying image of a mind flayer, which glows with an unwholesome green light. His cranium is grotesquely enlarged, and innumerable inger-length tentacles erupt from the skin, wriggling about and clutching each other...
Tlusutin can take a free action to gain the damage reduction 10/- from the mingling of divine blood with its material form. Tlusutin can supress this ability with another free action. Once the damage reduction has prevented 40 points of damage, Tlusutin loses all benefit of the template, including this ability, except when otherwise noted.
A mind flayer that begins its turn with all four tentacles attach and that makes a successful grapple check automatically extracts the opponent's brain, instantly killing that creature. This power is useless against constructs, elementals, oozes, plants, and undead. It is not isntantly fatal to foes with multiple heads, such as ettins and hydras.
Food For Thought (Su):
If Tlusutin eats a brain it gains the answer to 5 questions as if having used the Mind Probe power. If the brain comes from a psionic character Tlusutin gains half its unused power points (round down). This cannot increase the number of power points past Tlusutin full natural total (156 power points).
Improved Grab (Ex):
To use this ability, Tlusutin must hit a Small, Medium, or Large creature with its tentacle attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and attaches the tentacle to the opponent's head. A mind flayer can grab a Huge or larger creature, but only if it can somehow reach the foe's head.
If a mindflayer begins its turn with at least one tentacle attach, it can try to attach its remaining tentacles with a single grapple check. The opponent can escape with a single successful grapple check or and Escape Artist check, but the mind flayer gets a +2 circumstance bous for every tentacle that was attached at the beginning of the opponent's turn.
Superior Mind Blast (Su):
This psionic attack is a cone 60 feet long. Anyone caught in this cone must succeed on a DC 19 will save or be stunned for 3d4+5 rounds. The save DC is Charisma-based. This ability is the equivalent of a 4th level power.
Manifester level 15th. Typical Telepath Powers Known (power points 156, save DC 15 + power level):
1st - Defensive Precognition, Detect Psionics, Mind Thrust, Psionic Charm, Vigor
2nd - Body Equilibrium, Ego Whip, Id Insinuation, Psionic Levitate, Psionic Suggestion, Read Thoughts
3rd - Body Adjustment, Dispel Psionics, Mental Barrier
4th - Intellect Fortress, Psionic Dimension Door, Psionic Dominate
5th - Metaconcert, Mind Probe, Psionic Plane Shift
6th - Co-opt Concentration, Fuse Flesh, Mass Cloud Mind
Rebuke Undead (Su):
Tlusutin can rebuke or command undead as a 3rd level cleric.
Typical Cleric Spells Prepared, caster level 7th (4/3/2 per day; Save DC 14 + spell level):
0 - Cure Minor Wounds, Guidance, Inflict Minor Wounds, Read Magic, Resistance, Virtue
1st - Command, *Detect Secret Doors, Endure Elements, Entropic Shield, Obscuring Mist
2nd - Augery, *Detect Thoughts, Enthrall, Zone of Truth
3rd - Cure Serious Wounds, *Divination, Locate Object, Speak With Dead
4th - Dimensional Anchor, Divine Power, *True Seeing
* Domain spell.
- Knowledge and Mind.
Unholy Mind (Su)
: Anyone who attempts to use a mind-affecting power, spell or other ability on Tlusutin must make a DC 19 will save or be affected by it's superior mind blast ability. Tlusutin does not have to be aware of the mental intruder, nor is it limited by distance or direction.