Here's what I've done so far. Terrene is my world. The vampires have a similar origin and could probalby be looked at as a spiritual disease.
Template
Type: as creature was but gains subtype of augmented
HD: as by class
Speed: unchanged form previous race and class
AC: unchanged from previous race and class
Alignment: may be any but the nature of the need for blood tends to alter alignment over time to non-good.
Special Qualities:
Bite attack – Acts as a 1d4 magical attack that is at –4 unless target is grappled or flat footed. Once bitten, the target must make a DC 15 Will Save to perform any action. The vampire may do an automatic 3 points of damage via blood drain which goes to raising the vampire’s Hit Points. A Terrene vampire may not raise their hit points above their maximum amount via this method.
Damage Resistance - Due to their non-living nature, Terrene Vampires have a 5/slashing, fire, sunlight or magic damage resistance.
Unliving - Due to their unloving nature, Terrene Vampires do not need to eat, drink, or breathe and do not suffer any effects from not doing so. They also do not age from the time time they are created nor change in appearance in any significant way. Their hair remains as it was when changed and if cut will grow back during the day. Heal spells also do not do any good for a Terrene vampire but they do not do any harm. If taken down below 0 hit points, the vampire is not destroyed but rather goes into torpor and will remain such until given large quanities of blood. If a vampire in decapitated, goes to 0 or less hit points due to fire or sunlight, or suffers a negative amount of hit points to the max hit points, they are destroyed. Also immune to poisons and desieases unless encounterd through blood that the vampire drinks in which case they affect the vmapire as if they were of the type whose blood they drank.
Vampiric Feats - a Terrene vampire gets three vampiric feats when created.
Weaknesses:
Suseptable to sunlight - Direct sunlight does 1d10 damage per round and indirect does 1d4 pre round. Inorder to use any damage resistance such as that given by vampiric feats, the vampire must still make a DC20 fortitude check or take full damage.
Day Sleepiness - A Terrene Vampire normal falls into a deep sleep during sunlit times. To remain awake during the day, they must make a DC 25 Will check. If made they may stay away for the day. If sleeping and disturbed, a DC 15 Will check is needed wake for a number or rounds equal to the amount the modified roll made above the DC. The roll is modified by an amount equal to any damage the vampire has taken since falling alseep. This modifier is doubled if the damage was from sunlight or fire.
Blood hunger – Although a Terrene vampire does not need to eat, they do loose one hit point every day as they sleep.
Create Child - By giving at least one HP of blood to a freshly dead and drained intelligent humanoid, they gain the Terrene Vampire Template with as many Hp as was given to them.
ECL: +2
Terrene Vampire Prestige Class
Prerequisite: has the Terrene Vampire template
HD: d8
BAB: Average
Fort Save: good
Dex Save: good
Will Save: good
Feats: gains two vampiric feats every level
Class Skills: remain as any other class
Skills: 2+ Int modifier