Kirigaya-san should count herself lucky that she's still alive. But man did she get demolished real bad. Can't say she didn't have it coming though. She reaped what she sowed, plain and simple. Serves her right.
I agree with Cryssoberyl and DeltaCZ. Kirigaya did not have a revelation that she was bad towards Tadokoro-san. She's just crushed that her beloved Nikaidou thinks so poorly of her now. Anyway, at this point the "bully arc" is pretty much wrapped up so there's no reason for Kirigaya to be included in the story from this point on. It'd just make things needlessly complicated. Maybe we could have one chapter where Tadokoro-san and Nikaidou-san have a heart-to-heart chat with each other about what happened, but after that it's back to fluffy good times with them.
Also, for some reason Kirigaya's villainous breakdown reminds me of those murderers in the Ace Attorney game series, when they get exposed for their crimes and they completely lose it. Here she quite literally reduces herself to a pile of snot, which is exactly what she is.
