"Good to know, I guess?" Ari says, clearly having not noticed her girlfriend's confusion at Jaime's reactions or her shift to understanding on hearing the explanation. "Anyway, magic can do all sorts of things. As far as we know - and by we I mean anyone, not just specifically the two of us - it only affects living things, but other than that it's a pretty wide field of possibilities. You can do shapeshifting, flight, illusions; there's healing..."
"Most of the things that are traditionally associated with vampires don't come automatically with turning, but you can do a lot of them yourself: not needing to breathe or eat, enhanced senses and physical abilities, that sort of thing."
"Yeah. And so there are really only two major differences between vampires and regular people: humans - okay you could make a case that vampires are just a subcategory of humans but for convenience's sake I'm going to use the term to refer exclusively to people without the ability to get magic powers if they bite other people real hard - humans get magic by having their blood drank by a vampire, and we can burn through that magic to create direct effects on the world. Vampires get magic by drinking blood from a human - they can drink blood from another vampire, but it saps magic from the drinkee instead of giving it - and while they can use it to get direct effects, it's generally way less efficient than it is for humans. What they can do, though, is develop skills, so that if they try to do a certain thing, it takes less magic actively poured into it. If you do that enough, it gets to a point where no additional magic input is required; you can just do the thing at no cost."
"But if you push a skill too far or try to develop it too fast, there can be drawbacks. They have some variance from person to person and with the details of the situation, but generally it's something...fitting? Like, um, I know of somebody who increased their physical strength too fast and ended up unable to tell how much force she's applying, and now she just constantly breaks stuff. And there was a guy who went in for reflexes and agility; he's got kind of a hair-trigger; he'll hear a mildly startling noise behind him and be across the room before he even notices."
"We haven't actually met anybody like that," Ari clarifies. "You just hear stories, mostly. It isn't that easy to mess up that badly by mistake and no one's exactly willing to experiment with it, so there's not a lot of data about what drawbacks things have." She contemplates for a second. "Oh, right, why haven't you heard of it - it's not exactly a secret, we're not going to have to kill you because we told you about this, and we won't get in trouble ourselves. I think it's just sort of running on momentum at this point? Nobody feels like taking a few hours with every stranger they meet to tell them about it, and nobody's made a grand reveal to a large audience yet. But some places lots of people know - Switzerland has a weirdly high proportion, and a few other places do too."
"And there aren't really that many vampires, either. The population is growing, sure, but I'm not sure there's more than a few thousand globally right now. And a lot of them are I think using magic as a way to get a lot of money and are pretty content being one of a small number of people with their skillset."
"And yeah, as Ari said, anyone can do magic, you just need to convince a vampire to drink your blood on either a long-term basis if you don't want to turn right away or just a few times if you do. I don't really have an opinion about whether you should that isn't on the basis of 'I would probably have to be the one supplying you with it.'"