nebulosthe whole premise of Erika is imagining someone with perfect social awareness, and how that erodes her sense of self. and then when she does exert her self-ness, well, shit goes down, to say the least.
since she's a foil to Sebastian, you might imagine that he has an opposite awareness - a good sense of self but poor sense of others - but in practice it doesn't really work out like that. I think Sebastian has actually a parallel arc, and in some ways his own development comes from building an understanding of Erika.