Even if she had used a spell card in attempt to harm him, B. Battler was nowhere to be seen, but he was still around somewhere. It's just that he was not in the closed confined room that Flandre was trapped within. Suddenly, the barrier's walls began to close in, closer and closer to where it would eventually squeeze up Flandre in-between the walls.

The Seven Stakes were just that fast to avoid the seven Flandres attack without even trying to in the first place.
---
"It is a pleasure to meet you both. I'm known as Bernkastel, the Witch of Miracles," the Witch says with her usual emotionless voice, and she glanced at Ruby since she knew that she would introduce herself next.