Okay, when he put it that way... "It's... not exactly an easy thing to phrase in a comforting way, is it? I'm sorry. I don't mean to frighten you. I just really need something that will fight back when I try to use this spell on them in order to really be sure it's working properly."

Still, his reaction is not only entirely understandable, it's more or less what she expected. "Just... let's forget about that request, shall we? I'm sure I can find another way to test it. And I know my other spells are working, so it's likely this one is too, right?"