"I'm a cleric. We are a kind of spellcaster; we can't cast spells without the endorsement and backing of our patrons and are chosen for this privilege by being well-suited to advancing our gods' interests in the Material. Acting by proxy like that is presumably less expensive than most other ways of affecting things."

"Yeah, we don't have that. Uh, as for Milliways, I don't know who or what created it or made it connect to our worlds, but it seems like if they had made an agreement to limit their intervention in your world then they would ... not have done that, it seems like a pretty extraordinary intervention even without the books. The book prices are reasonable."

"Also, I should bring this up now, I'm using magic to speak your language and it will only last about two hours. Milliways has a permanent translation effect but it only works inside."

"I didn't prepare any language spells today but tomorrow I can prepare Share Language a few times - not enough to cover your entire party, unfortunately."

"You should check that it works before you prepare it multiple times, I think that even if I learned your language nonmagically I couldn't actually speak it, my mouth physically can't make a lot of the sounds. I was a little surprised that this spell works—on that note, I want to try teaching your awakened horses our language, I think they wouldn't have that problem and then they'd be able to communicate with you if they had this spell cast on them." Actually she'll get Fluttershy to do it, probably she will end up with more important things to do.

"I know of a technique for making spells permanent, but I don't know it by heart and all my books are back at home. Do you have that here?"

[tl;dr of the previously promised essay: Twilight is a nonstandard sorcerer/wizard gestalt that gets both prepared and spontaneous spells out of a common spells-per-day cap. I'm not sure whether she has two casting stats but she might.]

"Permanency is a known spell but it requires expensive quantities of diamond dust and a fifth circle wizard."

"It does require—but not—are diamonds very rare here?"

"...yes."

"They're not that rare in Equestria. They're one of the harder gemstones to farm, but not so much that—a Permanency would be a major expenditure."

"......well, we can't farm them, we have to mine them out of the ground or the Elemental Plane of Earth. Do you... know how to farm them...?"

"I don't know how to farm them; that's earth pony magic. You should talk to my friend Pinkie Pie, she grew up on a rock farm."

"Ugh, why?" says Pinkie Pie, in perfect Taldane. "Rock farming is boooring."

"Well, if you get them large enough they can be used to resurrect the dead."

"You can't do it the way earth ponies do it. You should try growing seed crystals in an atmosphere of 1% methane and 99% hydrogen at 800 °C and 3.9 psi in a demiplane with no gravity and looping spatial geometry, I've heard that works here."

"You can also just buy them from us," Twilight says apologetically. "—wait, you can what?!"

"- seed crystals in an atmosphere of - one percent methane and the rest 'hydrogen' at - eight hundred degrees of what? - three point nine what? - no gravity looping spatial geometry - someone write that down - you, write that down -"

Pinkie Pie does not offer clarification.

"If you aren't able to replicate, uh, whatever it is she said, a lot of ponies in Equestria would be very happy to trade with your world—or, uh, at least the factions in your world that aren't evil. You'll need to persuade our Princess to allow contact, though; she's very concerned about your world's evil gods getting into Equestria. That's one of the reasons we're stuck here."

"... also, uh, say more about the resurrecting the dead thing?"

Yeah he was not expecting to get two chances to memorize surprise diamond farming information. He ignores Twilight till he's confirmed that the random person he assigned to writing things down has succeeded insofar as that was possible and tells them to find a wizard who can copy it and give it to Lt. Sauer along with an explanation to send along to important parties.

"- I'm sorry, I've missed some of what you said."

"The main obstacle to trade between our worlds, for diamonds or other things, is that our Princess is concerned about your world's evil god situation leaking into ours, but, uh, I don't think I actually understood the evil god situation very well when I told her about it, so—is she right to be worried?"

(It occurs to her that she didn't ever check whether this man's god was evil, but probably if he served an evil god this would be—obvious somehow, right?)

"- the gods don't dwell on this plane, but they do act here, including evil ones, yes."

"Act how?"

"Principally through clerics, so I would expect the bulk of the issue to be obviated if you simply didn't permit or screened travel by Golarion natives and didn't allow anyone non-Good from your home to visit here."

"I'll tell the Princess that whenever I see her again. How do you tell if somep—I mean, someone is good? I mean, most ponies are but if they're not they're probably going to try to hide it."

"... also, did you actually say earlier that your world can resurrect the dead?"

"There are spells that detect alignment but only in sufficiently powerful people, empowered followers of gods, and outsiders and the undead. And yes, there are several spells that can raise the dead with different sizes of diamond and circle of spell trading off against different intactness and age of remains available. I can't do this personally but I have used a scroll of Raise Dead before."

"That's—I know some ponies who would be very grateful if your people could do that." She's suddenly very glad Applejack can't understand their conversation, in case it turns out not to work on ponies or something. "Our world can't do anything like that, aside from—rumors of old dark magic that most ponies won't talk about even though they think it's a myth. Sombra's empire—" She shudders.