"BB," the Sakura-look-alike replies. "Or your phone… oh, what did you call it? Ah yes. 'Artificial Assistant' was what you called me. You were much too stupid to realize you were talking to a servant I suppose."
Rin recoils, taking several steps back. "You were…"
"Yes." BB replies, teleporting behind Rin and leaning close to her ear.
Rin yelps and leaps forward, spinning around to face the grinning BB.
"You asked me so many questions when you found I could respond, but you never questioned that. Too stupid to realize that little niggling voice suggesting you seek the aid of that Church NPC wasn't your own in your dreams, too stupid to realize that Shirou hasn't been hunting you." BB laughs, and she laughs hard and ugly, hands wrapping around her stomach as pure joy erupts from her. "You thought I was some form of 'assistant'! You're stupid in every universe."