Cam is dipping a grilled cheese sandwich into a bowl of tomato soup when he feels the summons. He goes ahead and grabs it. Doesn't even drop the sandwich.
"What exactly does being a demon, angel, or fairy mean, exactly? Apparently if I become a demon I can conjure things out of nowhere, but I wouldn't expect it to require a... species name? ... unless there was some other major difference. The wings and tail are definitely at least part of it, but I would rather not assume."
"The three species are collectively called 'daeva'. You wouldn't start out with wings, let alone a tail, you'd have to make those yourself - or if you were a fairy you'd have to take a sort of potion thing they have in Fairyland if you wanted a set, but that'd be optional. Fairies are telekinetic, angels change existing matter. Daeva are also indestructible, though I'm not sure I'd bet on that against magical harm, there just isn't any on offer at home."
"Summoners who are kids tend to age up a bit but then stop. I'm a hundred seventy-two, myself."
"That is a much better deal than I got. Agelessness was forced on me at twelve, and now I have to keep inheriting everything from myself every five years or so. It's very awkward."
"That sounds very inconvenient. If it turns out that summonings and dismissals from here work the same as those from the usual destination, an angel may be able to help you with that, although it'd be tremendously complicated and delicate. If it doesn't work the same, I might be stuck here forever, or you might not be able to get anyone else, or - something else may be in effect, I don't know."
She shrugs.
"In any case, I'm glad to hear that I now have a decent alternative to going insane in another century or so."
"It's a side-effect of my particular brand of immortality. Instead of dying from old age, you get about two centuries at the outside before your mind goes. No-one knows why, to my knowledge."
"Well, that's a raw deal. I can't guarantee you wouldn't keep it if you turned into a daeva, though, there's no precedent for daevahood interacting with magic."
"Loads, but I'm not sure where to start; this possibility hasn't actually occurred to me before. List some social problems?"
She lets out a small breath.
"Alright. As far as this castle can be said to have a real location, it exists in Shadescast, which is a vampire city. I am a vampire. Vampires are hated almost everywhere else in the world, for good reasons: the vast majority of vampire culture sees humans as little more than slaves, chattel, and food. This is a result of a bad power structure, which has been further corrupted by horrible and or insane people in power. Vampires need to feed on blood from humans every month or so on average, requiring no other sustenance: animal blood doesn't work, it has to be blood from a thinking organism. Side-effects of chronic or acute exposure to vampire feeding include short or long-term memory loss, fugue states, and catatonia. Given vampire attitudes towards humans, few of them are careful."
"Well, that's terrible. How safe is this to experiment with? If I make you some blood, and it turns out that pins all the side effects on me, what am I looking at?"
She smiles, showing her fangs now.
"Would you care to try the experiment?"
"Maybe. One sec." He makes a black stick-shaped device, and without appearing to manipulate it in any way, sets it up to reflect the immediate surroundings. "Marker," he says to it. "Recording a test of offering this vampire here half a cup of blood designed to be from the hypothetical offspring of, oh, let's say C.S. Lewis and Joan of Arc, I think I can be tolerably sure they have never actually reproduced." He looks at Isabella. "How do you take it? Teacup? Straw? Aerosol?"
"Teacup. The fangs are instinctual and unnecessary. As far as I can tell from biological study, Vampires don't actually digest blood; we must gain nutrition from it in some other way, but..." She shrugs.
Cam makes a prettily patterned little teacup. He thinks for a moment, and it fills with blood, and then he hands it over.
"You're certain that this is blood? It's absolutely tasteless."
"Yep, it's blood, but it's from a person who doesn't exist. They could've, but do not. Okay, I'll try some of what would have been mine back when I ran on biology." He makes another, matching teacup, puts a dram of blood in that one too, and offers it, crossing his fingers.
She swallows.
"Equally tasteless. It's odd: animal blood is violently repellent to vampires. Human blood tastes vaguely sweet, with variations by person. This... is neither."
"Okay. ...I'm going to give you a quantity of blood belonging to a real person who is dead who has spent no time as a daeva. But they were a total jerk so I don't mind mildly inconveniencing them for science." One teacup of Hitler blood.
"Could it be that created blood doesn't work for some reason?"
"Yeah, looks like it. There goes the cunning application of demonic power to the problem of blood supply. Damn."
"Perhaps it's somehow related to the fact that if you feed off someone until they go catatonic, you stop being able to draw sustenance from them, even if they still have blood left. I haven't done this experiment myself for obvious reasons, but I have confirmation from multiple vaguely trustworthy sources."