It's impossible. Didn't you girls already have your wishes granted when you became magical girls? Did you not have your despair become hope?

...converting despair into hope?

Can't it be the other way round? In other words,

Hey Kyubey, why do your species obtain energy from the conversion of hope to despair in humans?

<s>srzly?</s> This can't be...!

Yes it's true, but if Madoka were to defeat Walpurgis Night, she'll become the most evil witch, the witch that will destroy this world.

Homura-chan, what Kyubey said, is it true?