Kareen didn’t try it before invoking Deagon Fairy Elf Witch so she doesn’t grasp the counterfactual! She just knows it works. And she’s pretty sure the school having more mana to do things with is good.

Plus, she likes doing nice things for entities she likes, and she is rapidly coming to adore the school. What neat magic it has! And this library! Is Heaven!

When students begin trickling into the library after the class period, she’s still wandering the stacks, examining and handling books, and occasionally pressing another crystalful of mana into the school.

Everybody's in a notably chipper mood, including her old pals from the British-and-American-enclaves end of the room, but it's hard to find people in the stacks and nobody's hunting her down that aggressively.

El finds her in an intersection. "Oh hello."

“Hi! I used Dragon Fairy Elf Witch on the school and now I have my own pocket dimension.”

"You are proper bullshit, what will you ever do with a pocket dimension?"

“I am such bullshit. So far I’ve been—okay I want to warn you that you’re going to call bullshit again—I exist, here, and inside the pocket dimension, at the same time. So I’ve been using it to read and do other things simultaneously.”

"Huh. Like you're... your own entrance gate?"

“Yeah!”

She holds a book; it vanishes from her hands, and then reappears. “I can send stuff back and forth—I suppose I don’t really need to, with most things, since I can just make more, but for a person it would be different. I offered to show Nia and she said I should make the experiment before breakfast tomorrow in case I’m wrong about it not being nauseating.”

"Induction is memorable in this way. Isn't that expensive - I suppose you've got an embarrassment of mana and maybe being part school lets you hold more? -"

“…I don’t know. It hasn’t seemed expensive so far? I have no idea how much mana I can hold, I didn’t know there was a limit so I didn’t think to check what mine was before I became part school.”

"That's why we need mana storage."

“See, that makes perfect sense, but I have been doing so many things that I haven’t necessarily sat down to work out all the obvious implications of everything.”

“…I bet I could use More Magic to make someone else part school. If you wanted to see if that bumped your limit any.”

"I don't know that I like the school enough to wish to adopt it as a relative. Nor for that matter can I get away from it easily enough to want it on the other side of the family. You got anything for trading in a bad affinity?"

“Hm! Not yet, but I might be able to work something out. I think mine’s divinations. What’s yours?”

"I don't have a word for it. Bad...ness."

…Oh dear. That might in fact explain why Bella found her spooky and Kareen finds her familiar.

“Ah. Badness like evil, not badness like low quality, I’m guessing.”

"Yeah no like if I try to write a spell I get one to set off a supervolcano."

“That’s pretty impressive in scale! I—all my notebook powers are truly wondrous bullshit. But back home, all the magic I’d ever seen before the notebook? It was like that. Not in scale. I’ve never met anyone who could set off a supervolcano…maybe if they worked really hard at it for a long time. But. Magic back home was for hurting people, and you had to wrestle with it to get anything worthwhile. So you have my sympathies.”

"...thanks."

“You’re welcome. I’ll let you know if I find anything for affecting affinities. Or anything horrible that looks promising for repurposing into non-horrible stuff. Which I have lots of experience with identifying!”

"I mean, I do cast out of affinity, everyone does." Shrug.

“Oh, of course. But I might as well get something out of having grown up in a horror anthology.”

"I don't have any reason to be like this. As far as I know."

“It sounds like affinities just happen, yeah. And—I mean, I haven’t known you very long, at this point, but so far my impressions of you have been strongly positive.”

"A lonely way to be."