"Have you ever asked what makes Sunnydale such an attractive place for them?"

"Answers range from 'it's the nightlife' to 'I dunno, I was following that guy you just staked' to 'heard it was a good place to start an apocalypse'."

"Why would anyone want to start an apocalypse?"

"Beats me, but surprisingly popular pastime."

"Is everyone who tries just incompetent or what, how is this world still around..."

"I don't really know. I mean, there's me, but there's only one of me and nothing actually stopping people from trying to start apocalypses in Tibet and nothing that would let me know about them in advance, and my power set is really stupid even when they're courteously local."

"You have a power set?"

"I don't just go around staking vampires on a baseline capacity. You know how much force it takes to get wood through a sternum?"

"Not viscerally. It is not really something that has come up in my life before."

"It's a lot of force. I can do that. But it turns out that super strength does not substitute for detective work, magic power, etcetera, so I'm trying to pick up a lot of slack here."

"Did you just wake up one day and realize you were really good at killing vampires?"

"No, I woke up one day and realized I could descend stairs without fearing for my life, and then later a god sort of thing appeared in my bedroom in the middle of the night and told me I had a mystic destiny, had I not been getting my prophetic dreams, I was supposed to get prophetic dreams? but no, I had not. Glitchy prophetic dreams. I also can't identify vampires with a spooky sixth sense. Everything else I'm supposed to have is in working order, though, it's not like the mystic destiny is under other circumstances well-crafted."

"I'm not sure what sort of explanation I was expecting but it was not that."

"It's kinda dumb!"

"Did the god-thing say anything specific about the mystic destiny, or are you just vaguely destined to be mystic?"

"I'm 'the Slayer', I am supposed to kill evil shit, there is one of me, my predecessor was presumably killed by a nasty bitey and I will have a successor when one gets me - it was the middle of the night, I was in bed, I did write things down afterwards but I didn't have a chance to get exact words."

"I have many objections to this system, most of which I'm sure you've already formulated."

"I don't even get dental."

"But now you can summon daeva, so that's no longer as relevant as it might have been."

"Yes. This is a much niftier skillset with which to attempt world-saving. I will want further lessons."

"Those I can provide. Do you want to that before or after we investigate possible ways to pay a demon?"

"Depends, what's the curriculum look like?"

"Go over the elements of a circle in more detail, explain what makes up a binding, explore more of the standard bindings and how they fit those criteria, and how to construct a binding yourself. Different ways to target the summons, how to summon a random daeva, how you can specify a specific one. What sort of agreements you should make once you do summon someone, common errors to avoid, more sophisticated errors to avoid."

"Do 'em in parallel? I show up with library books and then do my summoning lessons for the day while you skim the books for discrepancies?"

"That should work. Oh, I remembered: one limitation to demons' conjuration is that they cannot make magic items. If there are any useful magical trinkets we can obtain easily, that's another possible avenue."