"If you cast too many spells in a very short time, you will build charge. More charge means your spells are more powerful, but they can backfire and hurt you or curse you."

Alright! Progress! That's useful information.

"What if you never cast a spell?"

"If you stop casting spells you will slowly discharge your charge into the environment. It is also possible to actively discharge but that's a draining process that can't be done too many times in a short time."

Why are all of this person's answers so weird.

"So if I never cast any spells, nothing bad will happen?"

"You only build charge by casting spells."

"And there are no other drawbacks than this charge thing?"

"If you use a spell against another spellcaster, they might turn it back at you."

"Okay, but... Look, what I mean is, it seems like there aren't a ton of spellcasters around, even though information about you guys is publicly available, so... what gives?"

"I don't understand."

"Why isn't everyone trying to become a spellcaster?"

"Anyone who wants to become a spellcaster can just ask one of the Sages for a Rite of Ascension."

"...I feel like we're talking past each other, here."

"We can talk about whatever you like."

"Why are there so few spellcasters?"

"I don't know."

Thank you for the straightforward answer to his question no bad Peter don't snap at the clearly senile old lady.

"The only drawbacks to being a spellcaster are spellcaster charge and the fact that other spellcasters can turn my spells against me?"

"You can also turn other spellcasters' spells against them if they try to harm you."

"Okay but that's not a drawback that's an advantage."

Smile.

Arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh.

"You said there were multiple Sages? Can I find another Sage to speak to?"

"There are three Sages: the Sage of Practical Magic, that's me; the Sage of Mischief Magic; and the Sage of Untamed Magic. You can find them around here."

"Okay! Thank you, I'll try to find them," and maybe they will be less absolutely useless than this woman no actually she was pretty useful just a little bit slow and weird.

She seems to consider this to be the end of their conversation, and gets up to go grab a book to read.

...maybe going kind of asocial like that is a consequence of magic. If magic rots your brain that'd be a pretty great reason to not do it!

Peter gets up and resumes exploration of the place.

The ground floor has two other similar rooms to that first one, with books and a cauldron, and one of them is occupied by someone brewing a magic potion. They don't notice Peter, and since they don't seem to have a floating rune above their head he decides to not pester them. There's also a small bathroom and a kitchen, which is only sensible, really, but that concludes the mapping of this floor and the only places left to explore are up—and downstairs.

He decides to go downstairs into the basement first, and said "basement" consists only of a single room very much like the first one he went into. But more relevantly, said room has two people talking to each other, one of whom has another magic rune floating above her head. So he folds his arms behind his back and waits for a lull in their conversation to butt in.