[quote=@Draconis Nevyn]
That's sweet, and I think fairly accurate. I like to think Elle sees Zei as a sister too, older more mature sister. It'd definitely upset Elle to see Zei as she is, to look into her eyes and see the madness :P
[/quote]

Zei's madness is more of a subtle change. She's not going to go around laughing maniacally and shooting people. She'll become silent and will develop impulsive desire to kill in response to danger. She'll also stop being optimistic.

https://www.youtube.com/watch?v=GMmiPxti9EQ

This song captures what's happening to Zei nicely. Incidentally, this is Fatal Frame 5's ending song and that game deals a lot about killing and suicide.

[quote=@tobiax]
I can see how she might have come to that conclusion, but I'd be interested in hearing what's cited for that.
[/quote]

Unfortunately, I can't remember anymore and the past posts are gone so...