Bless Senku he really does go right into it explaining how it all works, but Dennis probably looks like he's blued screened. He's listening, but Senku may as well be speaking Greek.

"Yeah practice makes sense-" He mutters, nodding, trying to follow along.

"Still crazy you can do that much." And look if anyone could do that sort of thing, making a magic system, Senku is no doubt that person.

"So uh, like an item or something?" For focusing. He's trying.