[Icelander]

In a fantasy setting where the local culture is inspired by Babylonian/Mesopotamian culture, a PC has made the acquintance of a vampire.

I'm looking to define the powers, curses and weaknesses of such a vampire. So far, I've more or less assumed that it had typical D&D-esque vampire powers, because the setting is the Forgotten Realms, but given that several different parts of the setting have different undead types that still get called 'vampires' despite somewhat different statistics, I'll change anything I like to make 'Untheri' (the Mesopotamian-esque culture) vampires different.

The concept is that it is the physical body of a dead person* brought to life in a symbiosis with an evil spirit which inhabits the blood that courses through its veins. This blood, obviously, is not naturally produced by living processes by the dead body, but must be consumed from other creatures, ideally intelligent human beings.

The spirit might be called utukku, edimmu or rabisu, depending. They are generally not very bright, but extremely powerful. Their motivations appear to be fairly animalistic, enjoying a physical existence through the 'dead' host, whom they can enable to mimic the functioning of a living person using the power in their blood.

The spirits are entirely noctural, being dormant while the sun is above the horizon. This is the Nocturnal Disadvantage and during the hours of daylight, the vampire will therefore turn back into a corpse (though a recent one and won't actually rot).

I haven't decided what would happen to the comatose corpse if it were brought into actual sunlight, but wouldn't be opposed, in theory, to having this destroy the spirit completely and therefore end the magical effect keeping the dead body from decomposition, usually resulting the older ones rapidly turning to dust. That would be Weakness.

Sea salt frightens, repels and even harms the spirits, which implies it ought to affect the symbiote creature somehow. The spirits are also afraid of holy objects and cannot enter sacred ground. I'm thinking that an inability to enter homes without invitation sounds good and am going to retain that traditional vampire weakness.

In play, I've established that these vampires are not visible in mirrors and that they can appear human-like enough to require supernatural means or specialised knowledge to identify if they expend enough magical energy.**

I'd like them to possibly retain aspects of their former personalities, but to have all but impossible to control impulses from their blood spirit symbiote. That might be Uncontrollable Appetite, but would also be likely to be some of Addiction, Compulsive Carousing, Gluttony, Lecherousness, Sadism or other Disadvantages having to do with the spirit's excessive appetite for various physical pleasures.

The actual drinking of blood would indulge Euphoria and even Ecstasy, so many of them would be Addicted to doing it, even beyond what they actually needed.

I'm thinking that consuming the blood of one of these ought to have some health benefits, feel amazing and, obviously, be risky for exactly the reason that you'd imagine, i.e. that introducing parts of an evil spirit into your body is not a good idea and that it was designed to get you to be subjugated to the will of the one whose blood you drank and furthermore, to make you think that drinking more was a good idea.

It's been established that it can heal HP and FP that were lost to Bleeding, on a 1:1 rate, i.e. it costs the vampire 1 HP and 1 FP to heal the same for someone who consumes her blood. Should this be Healing, in GURPS terms, an Enhancement to Leech or some other Advantage?

What other traits ought a vampire inspired by Mesopotamian myths and legends have?

What are logical consequences of an undead being that is a symbiote of the former person and an evil, semi-sentient blood-drinking spirit?

What are interesting Mental Disadvantages that might suit a hungry blood spirit, which would be the things that made such beings 'evil', to most normal people?

Yeah, drinking blood is often considered pretty nasty, but I'm thinking that they should probably not be nice as nice can be outside of that. On the other hand, I do want them to be NPCs who can sometimes be reasoned with, albeit ones who have a terrible curse and tend toward terrifying, destructive behaviour.

Does anyone know what weaknesses vampires inspired by Mesopotamian myth might have instead of garlic, stakes or decapitation?

And should they mess around with something to do with their graves or should they perhaps all be people who were not properly interrred, so that they never had a grave? I'm thinking the latter sounds better....

*Perhaps one that was cursed in life, broke some taboo or was incorrectly interred. Perhaps one that somehow attracted the attention of a spirit or made a compact with one. Or perhaps the victim of a more powerful vampire.
**That is, if they spend ER or FP that they need to use Leech to recover.