On an unremarkable night in an unremarkable bedroom in an unremarkable city on an unremarkable planet, there is a girl. She is thirteen years old and turning away from the lesson on the holoscreen because she has just caught a glimpse of something flashing out of the corner of her eye. There should not be anything in her room that flashes.
"Come with me," says the white sister, "and I will give you the power to find a better solution."
"Come with me," says the black sister, "and I will give you the power to rise above this."
Elsewhere, elsewhen-
In an unremarkable bedroom in an unremarkable city on an unremarkable planet a young girl is getting ready to go out when there is a flash of light in front of her that is equal parts black and white.
Before her stand two young women, one dressed in all white and one dressed in all black, holding hands.
"Hello. We are here to offer you a choice," says the woman in white.
"To accept our power and become a magical girl," says the woman in black.
"Come with me," says the woman in white, "and I will give you the power to save anyone you care about."
"Come with me," says the woman in black, "and I will give you the power to do anything you can dream."
Elsewhere, elsewhen-
In an unremarkable room in an unremarkable city on an unremarkable planet, a girl is organizing her things. She looks up when something flashes in the empty center of the room.
Two young women holding hands now occupy the space, one dressed all in white and one dressed all in black.
"...So that would make you the Polemarch. And you the Imperatrix."
"What are the two most powerful people in the galaxy doing in my house?"
"We are here to grant you a portion of our power."
"To offer you the chance to become a magical girl."
"How come I've never heard of anyone becoming a magical girl before?"