Sadde's running.
Not for any particular reason, just because it's faster. He's been meaning to go to one of the capitals for a bit and now, he supposes, is as good a time as any.
And eventually he's not running anymore, because he's close enough to civilisation that someone might spot him. Not that he wouldn't be able to notice them by scent before they saw him, but still. And as he makes his way to the Norway capital at this more leisurely pace, he notices the tiny, shiny key. He walks towards it and picks it up and immediately notices just how magic it is. He can tell by the way the key feels like things, and different things depending on where it is.
He verifies that what the key feels like is consistent in absolute location by waving it around a bit and seeing that the same place always feels the same. "Huh," he murmurs to himself.
He straightens up and thinks. The first obvious thing to try is seeing whether it opens any doors—a universal skeleton key sounds like the kind of thing a magical key could be—but the second obvious thing can be tested right there and then. He pushes the key into thin air with some purpose, as if he wanted to unlock an invisible door, and then turns it, et voilà, the faintest of door-shaped outlines appears before him.
He locks the door, and it disappears. Unlocks it again, and there it is. So he pulls it open and sees—
"I think there aren't any demons where I'm from, and while extrapolating from two examples isn't a super great idea, two universes with humans plus something else, presumably demons are as rare as vampires in the multiversal scheme of things. But I get your point, I suppose, I'm just not sure what you want me to do with it."
"Nothing in particular. I decided to my satisfaction that you probably aren't too mind-controlled to issue valid consent a couple weeks ago. But it's still disturbing."
"Mm, yeah, there's a reason why I didn't list the ability to form mate bonds amongst my superpowers. All in all, between falling in love with you the regular way and the magical way, I'd probably prefer the former, especially if the end result was still this, but here we are."
"I mean, I suppose someone else might have given you the rundown on Hell if you hadn't been staring at me like that from the word go."
"If you're happy with it. ...Unrelatedly isn't it kind of a contradiction to be bewildered that I took a few decades to get around to having sex and annoyed that I ever did?"
"The bewilderment is a more conscious part of it than the annoyance. The annoyance is some primal instinct going 'mine,' the bewilderment is the very reasonable commentary on just how physically attractive you are."
"Okay, but, one, you're biased, and two, people can not-have-sex for reasons other than being physically unattractive, how is this unknown to you."
"I try not to, but if I didn't find the things I'd do sensible I wouldn't do them in the first place, and sometimes I slip."
"Okay, but requirements for under what circumstances one has sex aren't so much a 'sensible' or 'not sensible' thing."
"If in defiance of your prophetic magic thing we do not so much work out and I don't want to be celibate forever are we going to have a problem."
Wince. "If in defiance of my prophetic magic thing we do not so much work out, you having sex with other people will not be my biggest problem."
"...Do I need to worry about you flinging yourself into a black hole, what's the deal there."
"I won't fling myself into a black hole. I won't be as... enthusiastic about anything, but I'll survive, and I'll probably keep on trying to be helpful and prosocial and all that."
"Okay. Geez, this is such a - what's the protocol back in your empire for mating to people who are not vampires?"
"Telling them about it, giving them pamphlets, with some luck get the magic princess to impart instant knowledge on them, if it works out they become vampires too and the couple lives happily ever after. Forcibly turning anyone is a crime, for whatever reason, and for as long as one doesn't actually look at a potential mate, there's no mate bond formed, so if the culprit is found before their mate has finished turning they are removed from the premises with more magic so that the victim doesn't get into a relationship they don't want."
"That's... good. That implies that forcible turning is a problem that needed a solution."
"It very much was, under the previous shadow government the only law was 'uphold the Masquerade,' with a few non-obvious consequences like 'do not turn children,' but forcibly turning someone one had mated to wasn't just common, it was expected."