9.
The white thing makes her think of a mutant rabbit and a weasel having a baby and the thought is so disturbing Nagisa feels their pronouns change in the head for the briefest of instants.
A human's identity is fragile, they heard in a strangely distant sort of echo, soft and gentle. Almost. It was more like mother's gentle when things were going her way.
"Who are you?" they say, voice quiet in the nosy house.
It cleans a large, flopping ear piece. I am Kyubey! The fact that you can see me means that you have the potential to become a magical girl!
The word girl feels really wrong now but Nagisa knows nothing about how to deny it, how to change it. They want to. They want to say it's incorrect but she decides not to, because it won't make a difference.
"Well, whatever your earth terminology is!" it continues, seemingly oblivious to the roiling sickness in the human's gut. Whatever the case, I can grant you one wish, if you promise to fight a great and incredible power for us. We are working to save the universe, you see."
It speaks the same way mother does, except more enticing. Something Nagisa wants is in those words. Freedom is in those words. What will they do for it?
It's time to find out.