The demon scam

"Heck no!" you snap, feeling annoyed. "She's my little sister, okay? And she's just as much of a bother as YOU are, I'd say..."

Naria laughs and then gives a little smirk. "Well, well... Luckily for you, I'm in a good mood, so I'll let that pass. If you really want my help, I'll stick with you for a little while."

(Now you have the letter Z.)