He hops.

And they fly: up through the skylight, and then up through open air for a while.

Azimuth comes into view after a time.  It looks like someone tore a piece of the ground out of the ground and fixed it in the air, then built a military base on top of it out of trees and hung a bunch of organ pipes off the bottom.

"Hmm... could take you up through a drop shaft, dunno if I could pry one open with my feet or not... all the skylight are grated... fuck, this is tricky.  Um, tell you what, we'll land on the lip of the island, then how do you feel about riding on my back?  If you fall I am 100% capable of shooting down faster than gravity and catching you."

"If I fall the ground will be the worse for it, don't worry. Is there a use for riding on your back that's not merely being accompanied by you so I am allowed in?"

"My hands'll be free so I can fly up a drop shaft and pry open the door, 's'probably the only way in."

"Ah, riding on your back to the top of the shaft, I misunderstood. Yes, that's fine."

"Cool."

They land.  Tobin puts Sadde down, then turns around.  "Hop on again."

Hop.

Fly.

The drop shaft is lit from within with periodic globs of luminescent fungus.  The trip upward is extremely boring.

Eventually they reach the top.  The door is circular, divided in half.  Tobin reaches up and wiggles his fingers into the seam, then pulls.

He growls at the doors while he's doing so: "fuckin - I'm not a lindworm you dumb shit - take the goddamn hint - let me in you useless vegetable - "

Eventually the gap is wide enough for both of them to fit through.  Once they're inside, the doors snap shut.  He lands, lets Sadde climb off.

This room is also circular, made of some gray wood that looks and feels almost metallic.  It's lit by glowing blue-white mushrooms hanging from the ceiling.

"Okay," Tobin said.  "I don't know about you but that felt extremely stupid to me.  Let's go, I'll show you to Eleanora's office."

"I'm not sure you should blame your architects for not anticipating the possibility of extradimensional help who can't shoot themselves in the head to get here. But do lead the way."

"You're not a big jokes guy, huh."  Way: is led.

It winds, up staircases and down corridors and through the curtains-plus-squiggly-little-passageways that this world likes to use instead of solid doors.

And then Tobin leads Sadde through the widest curtain and squiggliest passageway he's seen so far, to a wide semicircular office...

...with a desk in the middle and a woman behind it.

"Hello, Tobin," the woman says.  Presumably this is Eleanora.  "Who is your companion?"

"My name is Sadde. I'm from another universe. I killed a dragon in single combat and was unhurt. I have other forms of useful shareable magic."

She leans forward and steeples her fingers.  "Really.  I'm very pleased to meet you, Sadde.  Do you prefer Tobin to stay here while we talk or are you comfortable speaking with me alone?"

"As the both of you prefer."

"Very well.  Tobin, you're dismissed."

He gives a casual sort of salute, and leaves.

"So," she says.  "Tell me about what you can do."

"I used to be human, but then I became what I currently am. My species—vampire—is ageless, does not need to breathe, sleep, blink, rest, or actually move at all; we do not get sick, we are extremely durable and if you remove a limb we can reattach it—and that's in addition to personal, unshareable magic I have which allows me to manipulate my own biology pretty much without constraints including doing things like regrowing limbs or turning them into spikes which I can drive into a dragon's skull, or generating pretty much any biological matter I want. We are very fast and strong, have much better senses than humans, have perfect recall of everything that has ever happened after we turned into a vampire, have ridiculously accelerated cognition and much more room in our brains. We also become much prettier after we turn. The only way to kill us is breaking us into pieces and setting us on fire.

"Now for the drawbacks. To turn a human they must be injected with venom, which is produced in greatest quantities in our mouths, and then over the next three days the human will suffer agonising crescent pain beyond anything you could possibly imagine or actually endure. It is very common to beg for death. There is absolutely no way I can overstate how horrible it is, and absolutely nothing I can tell anything or anyone that will actually prepare them for how bad it is. Newborn vampires are often so overwhelmed by their new senses that they have a lot of trouble resisting their every impulse, including murderous ones, but this is helped by advance knowledge of it. Newborns are also much physically better—stronger and faster—than regular vampires for about a year after turning. The perfect post-turning memory also drowns out most pre-turning events if the vampire doesn't particularly focus on them soon enough.

"We subsist on mammal blood—but nonhuman blood tastes worse than the worst rotten piece of food anyone's ever eaten, while human blood tastes and smells so good most vampires in my world used to be unrepentant serial killers because of it before the current government took over and outlawed murder. Because of this, it is extremely difficult to turn a human by biting them without actually eating them. Furthermore, drinking human blood makes a vampire less likely to be able or willing to resist it in the future, as well as more feral and antisocial and less capable of living in large groups. There is a set of instincts that completely replaces human ones which also automatically treats other vampires as threats and humans as food. There are associated physical changes beyond becoming prettier; a regular vampire's skin sparkles in the sun, our eyes turn red when we've recently fed on a human, gold when we've recently fed on an animal, and black when we're hungry, and our teeth are much sharper even in comparison with our hardened skin. And a vampire is always at least a little bit hungry, which is reflected in a burning sensation in our throat that echoes the pain of turning and only gets worse the longer it's been since we've last fed.

"When a vampire lays eyes on a person they would be mutually romantically compatible with, they are immediately and eternally in magical monogamous love with them; if the target is also or becomes a vampire, this becomes reciprocal. In case a vampire looks at multiple people they'd be compatible with at the same time, they get this mate bond with all of them. Female vampires cannot conceive, but male vampires can impregnate human females with hybrids, who take one month from conception to birth in a process that often kills the mother if special precautions aren't taken to immediately turn her.

"Any questions so far?"

"In your estimation, could a vampire who did not share your idiosyncratic magic defeat a dragon in the same way you did?  What were the biological characteristics, abilities, and limb configuration of the dragon you killed?  Am I interpreting you correctly that if an ordinary vampire lost a limb and that limb was destroyed, that limb would not be regrown?"

"Not the exact same way, no, but I expect it would not take much more work—I only resorted to the bone spike after I got fed up with playing nice, but I was not breaking a sweat yet, so to speak. It had two legs and two batlike wings, a long neck, and was somewhat furry. You are correct in that interpretation, but it is in fact rather difficult to remove a vampire's limbs and if they're not actually turned to ash it is possible to pick the pieces back."

"It sounds like the dragon you faced was a type called a wyvern.  Most wyverns have breath weapons - they can produce from their mouths dangerous substances, magical or mundane.  Most other types are more dangerous and more difficult to kill.  Dragon types are most easily distinguished by limb configuration.  I can elaborate, if you wish.  Dragons are not always made of flesh - some are composed of stone, metal, or more exotic substances.  Does that change your estimation?  How do hybrids compare with full vampires along the axes you've described?  Would sufficient fire or heat kill a vampire if they were not broken into pieces first?  Can vampires be harmed at all by extremes of cold, or by acid?"

"If these exotic substances are significantly harder than diamond that might make it more difficult but I expect a dragon would need to be perhaps an order of magnitude faster, stronger, tougher, and smarter before it posed us a serious risk. If the heat was sufficient to turn the vampire to ash on the spot that would kill them, the breaking-into-pieces requirement is just so the vampire can't put the fire out very quickly. Extremes of cold do not harm us, regular acidic substances do not either.

"Hybrids are... less physically enhanced than a vampire, but much closer to that than to a human, definitely much more than just halfway along. They also only retain perfectly memories which they choose to, have less attentional capacity and brain space, need to breathe, need to sleep—and in fact their need for sleep is a bit of a problem because although they sleep less than humans they always need to sleep every day at exactly the same time and wake up at exactly the same time and what time that is varies from hybrid to hybrid. They can also eat regular food and bear children and do not have mate bonds. That's half-half, though; other fractions of hybrid are different."

"Suppose a dragon was capable of keeping you on fire, by sustained application of a breath weapon, but not capable of turning you to ash instantly.  Could this kill you?  Can parts of your body be burned away without destroying you entirely - either an extremity, or a layer of skin or flesh over your entire body?  Some types of dragon don't keep their consciousness in their brains, and need to be killed by destroying a large enough fraction of their body; would a vampire be able to do so?  How does vampire venom interact with non-human animals?"

"This could kill me, yes, but the dragon would have a hard time keeping me in this situation. Well, this could kill a vampire other than me, I'm personally all but fireproof. A vampire should be able to destroy arbitrarily large quantities of dragon modulo aforementioned concerns about the possibility of much greater durability. Vampire venom kills animals."

"Noted.  I don't suppose vampires can fly?"