@CaitsBTW, Eris was talking about the mythological
Cassandra. Also, to explain why Eris is behaving like that, it's because she's still refusing to admit that Cassandra is taking over her mind that should be cold and calculating, instead of being filled with thoughts of desire and attraction for someone else.
However, it was only after she remembered that she made that vow after her older brother "betrayed" her that Eris became confused to the point of having that breakdown, since she really don't want to dwell on things that remember her of how it was to live with her crappy family. I guessed that it was quite obvious that Eris had some non dealt with psychological issues before (she isn't mad, just has some unhealed scars), but this should hammer it. Well, at least now, she won't have to take classes that day, right?
I just want to see what will happen when someone else goes into that toilet to find both Eris and the floor soaked, her hand bleeding quite badly and the mirror shattered. Actually it won't do much damage to her reputation, since Eris is supposed to be known for aggressiveness and such, in sum, one of the delinquents of the Academy that no one in their sane mind would associate with.
Well, sorry for the long rambling, people, but I just wanted to explain things that I can't IC, so that post doesn't look like it was out of character.
Also, following up with meaningful names, here is
Eris'.