Ahh, proving yourself to join a guild. The staple of RPGs. The GM was preparing for a heroic adventure, but the players managed to join the main antagonistic organization in the first session. He’s trying to go along with it, while at the same time giving the players a way to keep the characters ‘good’. It’s up to them which path they’ll take.

↓ Transcript
Makarov: Before I accept you into the guild, you'll have to prove yourselves.
Natsu: Wasn't beating up Salamander enough?
Makarov: That might have been an accident for all I know. You'll have to complete the task I give you.
Lucy: All right!
GM: You realize they're a bunch of criminals, right?
Lucy: Sure! We'll infiltrate the guild, and just wing it from there.
Makarov: Right. There' a member, Macao, who felt that the work was too much for him.
Makarov: He ran away into the mountains. Bring him back.
Makarov: No one leaves the guild!
Happy: It will be done, Master.
Romeo: Hey! You're going after my dad, aren't you?
Happy: What do you want, kid?
Romeo: Please don't kill him! Just... bring him back, ok.
Natsu: The we'll need to know how he fights. You can tell us, right?
Romeo: Umm... yes, of course. He um... uses... magic... Take Over magic. He turns into a giant ape.
Natsu: He's obviously lying.
GM: No, I just didn't think I'd have to come up with his magic so soon.