Charm: lbr Gansey is probably already charmed by Matthew in canon. It's impossible to dislike this kid. D'Artagnan typically likes people who are honest, honourable and generally good, and Matthew ticks all those boxes.

Lies: I'm happy for him to use this power around my boys! I try to put it in brackets if they're not being honest, but if you're every unsure, please just mention it to me and I'll clarify!