Archer
I know that smile all too well. It's the Illya/Tohsaka, "Yes, I know exactly what this can do, but you're not going to stop me from doing it, Oni-Chan/Emiya-Kun," smile, which means I'm walking around landmines here, Archer thought.
He smiled at the girl and said, "Call me Archer. The most you say, getting blown up is rather extreme. Unless you're hiding something up your sleeve. Now, if you're planning to blow up someone else, then I can't fix this."
He started to hand it back to her before he frowned.
Emiya, how did she learn that name? I use "Archer" here and that's what it says on the door . . .