Oh so that's the vaunted screamed line. It didn't sound like screaming to me, it sounded more like desperate, quiet-but-high-pitched, scared pleading.
Please pay attention to posts, folks!
How was I supposed to know that the thing I heard that sounded to me like a child's voice was actually a really, really high-pitched voice of a woman?
So that's Kyoko's voice... I find it hilarious that there does happen to be a child voice mixed in there as well anyway. (Or is there, even? Because if there is, I don't hear it anymore.)
Addendum: That high-pitched voice (now presumably Kyoko's) interrupts another line being spoken, by "good" Kyoko. That setup only makes sense if those are indeed two halves of Kyoko arguing with each other, because a flashback isn't going to interrupt a live line. The more (and more, and more, and more) I listen to this, the more it sounds like those have to be two independent halves of Kyoko arguing with each other. Bad Kyoko's first "Please die with me!" comes very prominently out of my right speaker before being answered promptly by Good Kyoko from the left speaker. Combined with Bad Kyoko shortly thereafter interrupting Good Kyoko with a more screeched and desperate (as if the last gasp of their fight?) "Please die with me!" suggests a battle between two active entities rather than an active entity battling with a mere echo from another's memories.