The bar was...unusually reticent, in the lower layers of her mind (and she hadn't pried further; she wasn't sure if she'd be noticed; she wasn't sure if offending would get her kicked out, and regardless of whether it was actually safe it was safer than anywhere else she'd been for the past...three years?) so she couldn't be sure this place wasn't really a trap of some kind, but the higher layers gave a plausible explanation that didn't involve being a trap, and whatever else it was warm and dry and had food. Her guard was probably a full 25% down. Positively trusting, these days.
"...Okay," Cerebella murmurs to Bella after a bit, "so, she's less, um, repentant than I had guessed, possibly to preserve what's left of her sanity, but she's perfectly willing to never do that again if I make her my kind of magical girl because if she works hard and manages to come up with a resurrection spell it is theoretically okay for anything to be okay ever again, basically. Also that kind of communication felt a little like the fluff's, but more...comprehensive."
"In terms of...sensation? Like how if you stick your hand in a bucket of water and then you stick your hand in a bucket of, I dunno, milkshake, it's really different but also there's a unifying feature of wet?"
She addresses her alt. "No offense, but so far our only interactions--on that level--were under your control. If you want me to decide to throw you at even more power than whatever it is you have--well, there's an obvious thing that it would be a touch hypocritical to object to, but of course you do, regardless, have the right to withhold consent."
"Mmkay." Mind Mirror! She steps inside.
"...I'm sorry," the other one offers after a moment. "I was. Um. I shouldn't have even tried and I'm sorry."
"I'm sure you are, right now in this nice safe environment with an alt to telepath at. I'm worried about what happens when you go home."
"I wasn't doing it because I wanted to. I'm--I'm not saying that makes it okay, but I was a traumatized teenager making terrible choices because trauma, not--a mustache-twirling villain who'd keep on doing it even if--" she glances worriedly at the mirror. "That's why I want more options."
"I'm going to leave it up to her whether to give you her kind of magic because she knows more about it on two counts."
"Okay." Pause. "When I first realized there was someone there and I couldn't even tell your mind existed I thought you were--one of the people who was trying to kill me because--back home there's only one thing that can do that. It's an alloy. The only amount of it anyone knows to exist comes from a helmet my dad had before they killed him. So. I--I don't know, I don't even know why I'm telling you this..." her hands are trembling.
"This is an interdimensional bar. There might be any number of reasons you wouldn't be able to read someone in here."
"It lasted for like half a second before I turned around and saw your bare head. I didn't really have time to think it through."
No, replies Bar, but only as long as it stays read-only.
"I mean, I think there are some people who can't help it," she offers, "...which even I think is bad but goes more in the 'innocently radioactive' category than the 'arguable supervillain' category."
"Sure, if they can't help it. But they'd better live in a cabin in the woods. With signs."
"Or around other telepaths who can do their filtering for them. We had a couple of little kids who hadn't learned to stop, back when there was a school." She sighs.
Bella sits down at Bar and asks for a recommendation and puts the resulting bottle of beverage into her shield.
And eventually Cerebella comes out of the mirror. "I think it should be fine," she reports.
"I'm not going to second-guess you but I'm curious about what makes you confident of that."
"...Part of it is that she's not likely to resort to unethical things when she has better options, part of it is...she thinks she can work up to a resurrection spell at some point, at which point she gets to answer to her version of Dad for any nonconsensual mindreading she did and Dad isn't fond of it either. Like, a lot of her terrible decision making is predicated on 'nothing can ever be okay again' and now she has evidence that it is theoretically possible for anything to be okay ever again, and damn is the inside of her brain a depressing place."