He fidgets delightedly. He is the tiniest magic nerd; it is him.
"I'm sure I'm a human," she says. "But it might turn out that I'm also very good at magic. We should experiment. What are some other things magic can do besides portals and translation?"
"I'd rather not experiment with fire inside my house," says Matilda. "Or near it. In case of explosions. What are some things magic can do that won't burn my house down if I do too much of them?"
He considers. "I'm kind of best at the blowing-up kinds, honestly. Mom always had a bit of a concentration in killing things."
He winces slightly as his fidgeting knocks his wrist against the table. "Speaking of healing, I'm pretty sure I have like three broken bones. So, if you're looking for stuff to do."
And she stares at him and concentrates very insistently on how he should not have broken bones and instead should be perfectly healthy in all particulars.
There is a ripple of light.
He is now perfectly healthy in all particulars.
He pokes his wrist experimentally.
"Okay, thank you, that is not how magic is supposed to work though."
"But it's- healing is hard, you can't get it without some tradeoff- do you have, like, a headache, at least? Do you feel out of breath? Did you sacrifice a newborn lamb while I wasn't looking?"
"No," she says. "I don't have a headache, I'm not out of breath, and I certainly haven't sacrificed any lambs, newborn or otherwise."
He looks around. "Anyway: this is a nice house. D'you have a mom? Failing that, d'you have food?"
"I have both those things. Jenny's at school right now, but the food is right here," and she gestures at several cupboards, which open.
He peers at the foods.
"I... may need advice, here. Are there any locusts?"
"There are no locusts. Would you like to try some things?" Various foods emerge from their various storage and float within easy grabbing range of Ari - a small stack of crackers, an Oreo, an apple, a handful of walnuts.
He waves a hand over them and utters a brief incantation; they glow white, and he begins nibbling on an Oreo. "Ooh!"
"Poison detection," he says offhandedly. "This is good! Where do you grow these?"
"We don't personally grow our food, and Oreos aren't grown anyway, they're made out of other things."
He tries the other foods. "Nice! Your dimension has good foods. Congratulations."
"Thanks. I'm glad you like our food, it would probably be hard to find you locusts."
"Locusts exist but people don't usually eat them that I know of."