the food chainKyouko believes that young witches, also known as a "familiar," shouldn't be killed until they mature into witches. The familiars must kill and/or devour four to five people before they can mature into a witch. Kyouko is willing to let more people die in order to achieve a grief seed. She says that there is no reason to "strangle a chicken before it lays eggs," meaning that she won't kill a familiar until it transforms and benefits her. Kyouko calls this process the 'food chain,' because it's how the life of a magical girl goes. The Witches will eat the weak humans, and then the magical girls will eat the witches for power and strength. Kyouko reiterates that being a magical girl isn't meant to be fun, its an animalistic form of life or death.
We find out from Kyubey that Kyouko is very strong because of the amount of grief seeds she has consumed into her soul gem. Her soul gem has plenty of room to spare in it because the grief seed takes away the impurities of the gem in order to let there be more light and room. When you have more room in your soul gem, you are able to use magic freely without worry. Characters like Sayaka are ignorant about this, which is why her soul gem turns black. She just wants to be a hero instead of understanding that to be a hero she also must save herself. Kyouko gets angry when people take being magical girl lightly because it can kill you.