"Not unassisted, not normally. There was one with idiosyncratic magic who could, and I can grow wings..."

"Does idiosyncratic personal magic come with vampirehood or is it a product of your world of origin?  You can't regrow limbs, but if you can heal fractures you must be able to regenerate flesh to some extent; could you regrow a layer of skin that a dragon burned off during battle?  A layer of flesh?  Can vampires receive transplants, either by reattaching somebody else's arms as you would your own or with surgical intervention?  Can vampire venom be siphoned and stored?  You say you can generate biological substances; does that extend to magical biological substances other than vampire flesh?"

"It is a product of my world of origin but sometimes vampirehood enhances it where it existed previously or creates it where it did not. I am not sure whether that was a property of my world, this is the first world I'm visiting where offering people vampirism is an actually appealing option. Layer of skin—probably, layer of flesh, probably not. Vampires can't receive transplants, other vampires' venom—which coats all organs and which is necessary to reattach a lost limb—burns us. Vampire venom can definitely be siphoned and stored but it's extremely corrosive to most materials, glass being the outstanding exception. As for magical biological substances, I have not yet been able to find a pattern on when I can or cannot create them."

"Do you know by what mechanism other vampires' venom, but not your own, is dangerous?  Is one of the magical substances you can create vampire flesh, and if so could you use that to contain vampire venom?  Does vampire flesh separated from its body of origin die or decay?  Could you create another vampire's venom, or does any venom you produce by any mechanism count as your own?  Are there any other useful magical substances you can create and would be willing to manufacture for us?"

"I do not know why other vampires' venom is dangerous and I cannot generate any but my own. I can generate my own flesh, though—or bones, probably better—and use that to contain vampire venom. Vampire body parts never decay—they may dry up if not envenomed but can be restored later. None of the magical substances I've been able to produce are in themselves useful, they are typically only magical in conjunction with other things or used as part of larger magic."

She nods.  "Is there any known way to alleviate the pain of transforming?"

"There was a witch—someone with a magic idiosyncratic power—who could completely shut out all senses of people in an area around him, including stuff like proprioception, but that's the only known method."

"If it's magically possible at all I'd expect it to be possible to engineer a way to do it using Wellspring plants, but that isn't my area of expertise.  Now, you mentioned you have other forms of shareable magic as well?"

"Indeed. It's really just the one but it's versatile enough to be able to do pretty much anything. It's called sorcery, and from the moment I walked into this dimension everyone in it was able to use it."

"Tell me about it.  I would appreciate a rundown like the one you gave me for vampirehood, but in particular: how difficult is it to learn to use, and can it affect magic from universes other than its universe of origin?"

He has given this explanation before. He can share all the details, too, since this world apparently is not going to torture or kill any people based on their hair colour with magic. He details all of it, including answers to the questions he's been asked before and clarifications on subtler points.

"To be clear, are gifts a different sort of idiosyncratic personal magic from the kind that turning sometimes gives or enhances?"

"They are. The idiosyncratic magic related to vampirehood does not typically run on a battery and tends to be personality-based or at least—influenced."

She nods.  "I think I'll want you to work with Zacharias, to find points of synergy between your magic and ours.  Zacharias is one of my best Wellspring engineers; he's in charge of several projects that could turn the tide of the war.  How familiar are you with our magic?"

"Tobin gave me a one-paragraph explanation of each aspect of it, but that's all."

"I can give you my explanation now, but as I say it's not my area of expertise, and Zacharias would have to fill in the gaps later; or you can wait until you've met him and hear it then, as you prefer."

"Waiting sounds best, then, least time wasted."

"I'll send him my notes on vampirehood and sorcery, and he can contact you when he's ready to go to work.  In the meantime, I can arrange for a room for you to stay in; based on your description of vampirehood it doesn't sound like you need very much to be comfortable, but do feel free to correct me if I'm wrong about that."

"I don't really need anything at all, not even a room. I could stay on a roof or some quiet corner.—I'd appreciate books, though, to pass the time."

"We have a library."  She gives directions, to his room and to the library and to her office and to Zacharias's lab.

"I presume Zacharias is not there?"

"He is, but he's working.  I'm going to have him look over my notes before he starts working with you, so you don't have to give the same explanations twice."

"Ah, I see."

Library-wards, then?

Librarywards indeed.  This particular library divides its books into "narrative" and "reference" rather than fiction and nonfiction, and further subdivides "narrative" into "bright" and "macabre" rather than any familiar genres.  The "reference" section contains mostly histories of Tairil, books on battle tactics geared toward small groups of powerful individuals fighting enormous monsters or armies of smaller monsters, and textbooks on magic.

Battle tactics seem most useful.