"Okay, that works for me. Once you've assimilated me, will you be able to give arbitrary bodies my magic?"

"At first I'm pretty sure I'll only be able to give bodies your magic by making them exact copies of you, but eventually we should be able to figure something out."

"How exact is exact? Couldn't you give them my genes without making them morphologically me?"

"Yes, but not trivially. And I don't currently know that what gives you your magic is exactly and only your genes. Consider by way of analogy the problem of constructing two people whose voices sound exactly the same even though they look very different, which I've done but which was very tricky to get just right."

"I'm not sure that's a very useful analogy because I can't see why that would be difficult either but I'll take you at your word that it is. Alright. Anything left to do before you tentacle me up?"

"The pitch and sound of your voice is controlled by the physical shape of your vocal apparatus and very small changes can have very detectable effects! —anyway, no, I don't think there is. Shall I?" She reaches an unraveling hand toward Angelica but waits politely for confirmation.

"Hang on a second." 

She takes off all her jewelry and places it on the desk. 

"Okay, now."

Once again, everything is coming up tentacles.

It's—not quite exactly painful but definitely very intense—and it's over very quickly, and then there's a sort of dreamy timeless moment of nonexperience, and then she's being reconstructed much more gently, flowing together into the shape she's familiar with. She can straightforwardly perceive everything that the Ellen in here with her is thinking, but most of it is in structures and sensory modalities that she's never experienced before, so it's pretty disorienting; which gives Ellen time to construct a second Ellen, after which Angelica can still perceive everything they're both thinking but now her own Ellen is mostly passively receiving the other Ellen's thoughts and senses.

"Okay," says other-Ellen, "so you're the master copy whose job is to stay home all day, and I'm the roaming Ellen, and it's probably a good idea to give you a minute to settle in before we make the roaming Angelica."

"Cool," she says after a moment to orient. "This is going to be interesting...oh, man, having this at home is going to be fun. And make it much easier to preserve my secret identity." 

"A secret identity! Exciting," says Roaming Ellen. (The Ellen sharing Angelica's body sends Roaming Ellen a contentless ping of communication to check that she gets it. They don't let this interrupt the flow of conversation.) "Those can be fun but the way I do it is mostly exhausting, having to set up legal identities for dozens of different researchers so I can work on a team with myself. The forged doctorates alone... so much paperwork!" Fortunately the people she's working for are more interested in results than in credentials, so she didn't have to try very hard. It was just sort of understood after a while that if she could wave the right pieces of paper around, no one would check if they were real. She never actually went in with a diploma scribbled on cardstock in crayon but she thought about it.

"Oh, I don't have to do anything like that, Eurydice Peverell sends people letters bribing them flagrantly with lost arcane lore and occasionally shows up at parties in a spooky cloak, she doesn't work for anyone she'd have to justify herself to with credentials or a legal identity or anything."

"The people working on studying the Blacklight virus want to hire people who will make them money, and I'm pretty good at recommending people who will make them money." Because those people are also Ellen. Though honestly the methodology of every non-Ellen researcher in the entire project is crap and sometimes she feels like she'd be better off ditching the whole organization and starting over from scratch herself. Unfortunately they have military backing, but hey, maybe Mind Control University will teach her how to deal with that obstacle.

Anyway, "Want to make yourself a Roaming Angelica now? Your Ellen can set you up—" and indeed, the Ellen in Angelica's head is already doing incomprehensible things with their presumably Blacklight-derived incomprehensible mental interfaces, weaving together a construct which can be completed if Angelica just holds out her hand a little and wills it so.

She holds out her hand and wills the construct. 

And lo, there is a second Angelica!

Getting the feed from her is a little weirder, because there is, as promised, an underlying Ellen. Roaming Angelica's experience is of being alone in her body, but behind her like a faint echo there is an Ellen, who is largely just scanning her senses for points of interest and not really paying close attention to her thoughts.

All together, with the feed from the two roaming bodies and the extra Ellen layer in Roaming Angelica, plus Home Base Angelica's own mind and senses, it's getting to be kind of a lot. Home Base Angelica's Ellen helpfully sorts through the input streams for her; reading them at one remove through her Ellen layer is easier and more straightforward than trying to track it all in raw form.

"This is interesting," Home Base Angelica observes. "I guess we'll be able to get more potion-making done while we're here than I thought."

"You are absolutely right," Roaming Angelica says, picking her wand up and putting the jewelry back on that she had removed. "--Actually there isn't much point in not having at least one me on potion-making duty at all times--this could increase our bargaining power exponentially, if we have not only nebulous lore but also, say, as much Felix Felicis as we could brew with half a dozen bodies--"

"Well, potion-making is still only so interesting, I don't want most of our experience of the world at any given time to be potion-brewing."

"That's true, but the potions that take a long time don't generally need to be attended to the whole time--and we could get so much done, if the only limit to how many of us there is is biomass--"

"Grandpa Cadmus is going to freak," Home Base Angelica observes gleefully. 

Roaming Ellen grins at their enthusiasm. "Okay, are we ready to go to dinner? We can bring more food back for you," she nods to Home Base Angelica. "And, hmm, we should figure out a designations scheme at some point; Ellens tend to name ourselves after our legal identities, but that's not how things work around here. For now we've got roaming instances and home base instances and Ellens acting as auxiliaries to Angelicas, but if we ever get into anything more complicated, we might need to start renaming ourselves. 'Home Base Angelica's Ellen' is already a bit of a mouthful."

"For right now, I'll be Eurydice," Home Base Angelica says. "Once there are more than two of us we'll need something more complicated than just giving one of us the alias we already have." 

"We should consult the others," Roaming Angelica muses. "--Ellen, I don't know how much of this you've inferred, but the reason we know there's an afterlife is the same reason we have all this lost lore to bribe people with; we have this magical artifact called the Resurrection Stone that our ancestor Cadmus Peverell invented and it can summon shades of the dead from our afterlife. We've been collaborating with him and his brothers who likewise developed things," she waves a hand, "I'll explain the Deathly Hallows later. The Stone is the only one we have, anyway. Likewise we know that the Nicholas Flamel who's around today is the original Nicholas Flamel and not the latest in a series of copycats using the same name because we can't summon the original Nicholas Flamel's spirit."

"Fascinating!" she says. "And I suppose you haven't had time to check if it still works here?"

"I mean, technically that's true," Eurydice says, going to the cabinet and pulling from one of the crannies a ring identical to the one Angelica is currently wearing, a gold band with a plain black stone, "but I asked Mesmerra if it would work here and she said yes." 

She turns the ring over, and an unattractive woman in badly-taken-care-of clothes appears, see-through and greyscale; again, and a man wearing extremely antiquated clothing joins her, again and again and two more men join the first. 

"Mother," she says, "Grandpa Cadmus, Uncle Antioch, Uncle Ignotus, this is my roommate Ellen, at the university I told you about."

"And who is that," "Uncle Antioch" asks, gesturing at the extra Angelica, "in the Polyjuice?"

"No, that's also me," Eurydice says, "Ellen can duplicate people. I'm going to use this ability to force-multiply aggressively, but once there's more than two of us we're going to need a more comprehensive identification schema than just calling one of us Angelica and one of us Eurydice." 

"Only you," the woman says, shaking her head fondly. Eurydice can't actually touch her but she can mime a hug, at least. 

"Ellen, this is my mother Merope Gaunt, my ancestor Cadmus Peverell, his older brother Antioch Peverell, and his younger brother Ignotus Peverell."

"Lovely to meet you all!" she says. "I wonder if we can figure out a way to make Blacklight interface with this thing for resurrection purposes? I'd guess it would be tricky if it's possible at all; Blacklight really loves biology and you, ah," she gestures broadly at the ghosts, "don't appear to have any. But it's a thought."

"It is a thought, but there's only one of these--the ring Angelica's wearing at the moment is a decoy--and I really don't want to risk breaking it." 

"There's not much point trying to make plans now, I'm sure we'll learn all kinds of relevant things once classes start," Angelica opines, "imagine if we'd tried to make plans about immortality before we first went to Hogwarts!" 

"Don't start," Eurydice warns Antioch, as he opens his mouth, "you may not have gone to Hogwarts, but I didn't have any other source of magic training at that point, don't be difficult, we've been over this."

(Ellen giggles. Angelica interacting with her ghost family has a similar air of familiarity and collaboration to Ellens interacting with themselves; it's pretty endearing.)

"After dinner I want to go to the library, we'll have to stop back here first to deliver Eurydice's food but after that. And if we bring the ghosts at that point that's more sets of eyes-on-books."

"True, but do we want to reveal that you can summon ghosts? What if someone mind-controls the ghosts?"

"Point. We don't know there'll be anyone at the library, but we don't know there won't...this would be more helpful if we had managed to recreate the Cloak already," she grumbles. 

"I don't think any of us would be able to wear it," Ignotus says, amused. 

"Yeah, but I could, and then nobody would know you were with me! And anyone who tried to mindcontrol you wouldn't know I had your back."