"It costs a little more, but the spell is more powerful if you use a focus, so it's still more efficient."

"Huh. Neat. And the artifacts make them most powerful of all, then? What are some spells you could teach me, and how were they discovered?"

"Sorry, maybe I'm explaining this wrong. Spells aren't discovered, almost anything will work, what you have to do is find which things are actually cost-effective."

"Oh! Almost anything?—should I just try to rhyme, is that what this was about all along?"

"Rhyming is how you draw attention to something. Wishes can happen without extra work, but spells have to be distinct from other language. Try rhyming."

"Okay, um... Wind, blow and flow, move under my control." Small breeze. "...okay this was really cool."

"It can be, yeah. Nice for a first try. If you have specialties, we should try to measure that, next. Some spells we know what the usual cost is...let me get my notebook, I have a chart." 

He goes, leaving her in the room unattended.  

She does some more magic again, and giggles.

He returns.

"Alright, so our family doesn't have any gender-shifting spells written down, but we can try stuff that might be close and see how much it drains you. There's some for affecting how old you look, there's some for getting taller...nothing really gender related but those might work." 

"Ooh, gimme the goods!"

He hands her a list. The spells he mentioned:

May Illusion hide from judging eyes the marks of age that we despise.

Let me grow tall, yet strong; hale, yet long.

The first one doesn't do anything. The second one does make her taller, by a fair margin more than the typical user would be.

"I think we're on the right track, barely any of us get anywhere with that kind of thing."

She beams. Then stops. "So, how many of these affinities can someone have? 'Cause magic is cool and all but if literally the only thing I'm good at is changing my body I will want my money back."

"I don't know if there's a limit, and you can do basically any spell when you're not running low. I probably should have warned you before we started playing around with it; you might need to recharge before trying anything else."

"Oh. How do I recharge?"

"Eating and sleeping, basically. If shapeshifting magic is your specialty, you'll be able to use a lot more of those-"

"-completely irresponsible! Someone could have gotten seriously hurt," they hear, as Mr. Argent's voice rises. 

He reaches for his belt and pulls out a card, from some sort of holster. 

"Libra, do not let the matter lie, if they tell another lie."

The card glows and disappears, being replaced by a set of floating scales.

...okay what.

She blinks at him.

He ignores her. 

"Come on, Chris, you know they needed a warning, they were trying to turn this deal into a complete joke! The Argents are no joke. If I hadn't stepped in, they would have completely cheated us." 

The scales move, moon and sun rising and falling in turn.

"Libra can tell when someone is lying. Helpful with this family."