Explain the system

The good news is, Sarah is nerd enough to actually understand what multiplicative inputs mean. The bad news is, her idea of kinky is gross.

"Have you tried weird poop stuff?"

"No. I don't have to try. I am absolutely certain that something that's utterly gross to me would also give me no magic. Also I think my dick would overwhelm my magic and just wilt."

"Whatever. You nominate me the official mistress of major ceremonies, OK?"

"I'm not sure what that means."

"It means that when you have the opportunity for a huge energy boost, like say Jill's cherry, I set it up."

"No. No weird poop stuff."

"I already said whatever. We'll stick to your perversions, but only if you fill out the spreadsheet I send you by next week."

"OK, fine. But only because you like spreadsheets."

"I don't like them. They're just the only way to get things done sometimes."

Fair. "You also have to consult with the girl involved. Her taboos and kinks matter at least as much, and she has to go along with it."

"Obviously. She's the star, you're just like, literally, the dick."

Mean!

She goes on. "Anyhow, Jill. Have you got the rest of the DnD group in on this yet?"

Jill looks at you anxiously.

Oh, DnD anxiety.

"I've played a couple games myself. It's cool to be uncool."

Jill grins and then tells Sarah "No. I wasn't sure how to get their reaction without risking our big secrets."

"I know just the thing. Can you juice me, dick-boy?"

You just give her a look of disbelief.

"Oh, fine." She grabs your dick from the open backpack and starts to undo her pants.

"No! I mean, sure if you want. I just don't want to be dick-boy. Call me Ed."

"You're such a derp. Fine. May I please have a medium sized dose of mana?"

You give her about a quarter of an orgasm worth.

"Nice! I should be able to buzz around for a while with this. And I think I know how to turn it off, too."

She races away before you can reply.

"You know she took the dick, right?"

No.

"Yeah, I guess."

"Is she doing anything with it?"

"How can I tell? I'm still buried in a bunch of girls. Unless I can actually see what someone is doing or it really stands out, it's all just awesome background sensation."

"That's kinda sad."

"No. No it is not."

With a rush of wind and motion, Sarah is back, and there are two more girls.

"These two passed the test and didn't pass out."

"Fuck you, Sarah. I should have known that was you."

"Let me guess. Hana passed out?"

"Bingo. Anyhow, this is Amy and Lauren. They need the lessons in holding and using magic, and a dose from Ed. Girls, this is Ed, the key to world domination."

"He's why you're super fast and felt the need to make us suck a dick?"

Jill looks at you like you had a bet on that.

"You didn't have to do it. You just showed you were willing."

"You left us on a ledge five stories up with a note and a dick."

Seriously?

"Seriously? And is Jacqueline not here because she didn't suck it? Go get her. I'm going to make you apologize before Ed gives you another dose."

"Fine! But she better earn her own way."

You look at the girls. Amy is a tiny cute pink-haired Asian pixie. She's like 4'10" and everything is proportional. You'd guess she was Japanese except her T-shirt says "Call me Japanese and I sepeku your nuts." Korean maybe? She has either much more perfect skin or more makeup than the other girls here, absolutely gorgeous eyes with loads of lashes, and lipstick the exact same shade of pink as her hair.

Lauren is slightly overweight, but at least plenty of it is in her boobs. She looks... happy. Your first impression is that she bakes cookies for everyone. She has slightly reddish brown hair that's a bit curly, and she's barely taller than tiny Amy. Her long sleeve shirt is just tight enough to show she has a figure.

Sarah gets back with Jacqueline, who is almost the opposite of Lauren. Tall, almost as tall as you. Thin, but elegant. Modelish, and wearing a loose dress. Black hair and dark eyes complete the stereotypical French look, but she doesn't have an accent.

Sarah is apologizing. "So, apparently I shouldn't have tried to test your resolve."

"I have plenty of resolve. I just don't suck disturbingly realistic dildos under duress. Either it was a shitty prank, or it was a serious crime. Either way I won't give them the satisfaction."

"Anyhow, we need to teach you girls how to hold mana."