Please do that. Do you see the witches on broomsticks at your three-o-clock -

I do now.

It won't, actually, take Karen very long to clean up most of the obviously dangerous things that are happening. She's a little limited when it comes to sight and navigation, but at these distances her flight speed can be pushed up to something approaching instantaneous, apparently without harming the people she's transporting.

I should get some of that fancy jewelry My - Matt has for attentional capacity, he mutters when obviously dangerous things have been made to stop that. Wishbone, any idea what's causing this?

I would be of more help in a proper library. Off the top of my head I'd want to check how far from the hellmouth the affected children are, their ages, what exactly seems to count as a costume, whether anyone else who's transformed seems to have retained their memories as well as Karen has...

Library coming up. I don't think it's very mysterious that I remember who I am; green lantern rings can pick anyone, so I'm just, like, Karen who was given a green lantern ring. Doesn't have to overwrite anything to make me a real green lantern.

- although I did just move a vampire who seemed super confused about stuff, and normally vampires can be anyone and can keep their memories too, so I dunno.

She flies her dog to the batcave and lets him in.

I mean, maybe they were a tiny kid, tiny kids are often confused about stuff even with all their memories. Sigh. Looks like less than half the college students in costume transformed, but most of the kids.

But no strict age cutoff. Not super sure what to do with that.

She flies up. 

Not noticing an obvious center of activity that things fan out from, either. We thinking spell? This is obviously a thing spells can do, given local transformed dog...

Possibly, although this sort of power is normally beyond humans, even when acting as conduits for other beings. The hellmouth probably complicates things. If we knew why only some of the costumed children had transformed, what the immune ones have in common -

He sends everyone a parade of untransformed costume examples in case anything stands out. Sexy nurse, sexy cat, Hermione, homemade robot costume, sexy professor, James Bond, homemade ghost costume, toddler in a well-worn pumpkin costume...

Uhhh, the spell is allergic to things that are beat-up or pointlessly sexualized?

It has standards!

Pff.

Maybe if you checked on some of your friends? Ones that you have background information on. See if any of them are untransformed.

Yeah, OK. Wanna find Dennis anyway, even odds he knows significantly more about green lantern lore than I do. Obviously Mercy was transformed.

He scans for people who might be Dennis. Know what he went as?

The guy from Men in Black. I don't remember the character's name. The guy Will Smith plays.

- well, could be worse.

Any signs of him?

Dennis is pretty sure his name is Agent J, but he's walking around town talking into a recorder and noting all of the evidence of extraterrestrial involvement here, because here's honestly too much of it for a straightforward mindwipe and at this point his superiors are probably just going to need as complete a report as he can provide them with.

Yup. He doesn't remember anything. Twelfth and Cypress.

On it.

"Dennis?"

"Ma'am, this is officia - and you're levitating, OK, that's new."

" - yeah, it is actually.  Man, you look exactly the same. You're not even wearing a real costume, that's just, like, a tuxedo you borrowed, you didn't even buy anything except the - "

Waaaait a second. I dunno about Dennis, but me and Connor and Mercy all bought our costumes from the same place? It - seems very improbable that almost everyone bought their costumes in the came place, but -

Where?

Some place, I don't remember the name. She remembers the location and flies there. The store is dark and obviously closed. Ethan's.

He passes this along to Wishbone and Giles. Let's start asking kids who didn't transform where they got their costumes.