9: “Madoka, do you know what the word “entropy” means?”
"To give a simple example, the amount of heat a bonfire gives off is not equal to the energy it took to grow the wood it’s made of. In short, when energy changes form, some of it gets lost. As a result, the amount of usable energy in the universe is decreasing. So we began searching for a form of energy that wasn’t bound by the laws of thermodynamics. And what we found was… the power of magical girls."
O: “What … are you?”
9: “Our civilization created technology that could convert the emotions of a sentient lifeform into raw energy.”
"Unfortunately, our species do not possess the capacity to experience emotion. So we studied various species throughout the universe until we found you humans."
"With the size of your population and the rate of your reproduction … the amount of the emotional energy produced by a single human … is greater than the amount used between its birth and growth. Human souls truly are the energy source that could counter entropy!"
"And the most effective of all are girls in the second stage of development…who experience the greatest fluctuations between hope and despair."
"The moment when your Soul Gems flare out and turn into Grief Seeds, enormous energy is created. It is (our job) to collect that energy…"
O: “Are we just disposable energy supplies for you then? Are you saying we should die for you?
9: “Do you know how many civilizations fill this universe and how much energy they use in a single moment? And someday, even you humans will be able to leave your planet and come join all of us. When that day comes, you wouldn’t want to find the universe empty and desolate, would you? If you look at it in the long run, this should be a good deal for your benefit as well…”
O: “Don’t be ridiculous… how can you say it was okay for Mami to die and Sayaka to suffer…just because of some crazy reason like that? That isn’t right. It’s too cruel!”
9: “But we always ask and receive your consent before making a contract - doesn’t that alone show our good will?”
O: “I can’t follow what you are saying. I don’t understand you at all.”
9: “It is we who have had such a hard time understanding you humans and your values systems. With a current population of 6.9 billion — that is increasing at a rate of 10 per every 4 seconds — why should you care so much about the loss of a tiny handful?”
"Madoka, I still believe that one day, you will become the greatest of all magical girls, and then the wickedest of all witches… when that happens, we will surely obtain an incomparable amount of energy.
"So if you ever feel like dying for the sake of the universe, please call me anytime."
"I’ll be waiting for you…"
—Puella Magi Madoka Magica, Episode 9, “I’d Never Allow that To Happen”
“I am what I am and cannot be otherwise because of the shadows.”