What was the point of sinking Kisaragi back on episode 3 now?
I would say it added suspense and some parts of seriousness and paranoia from the viewers. They weren't the first one to try it, Takahiro pulled the same bullshit in Yuuki Yuuna.
But all in all, it was really just a dick move to get people invested, as well as piss off Kisaragi fans. If anything, it was about as pointless as giving the Akatsuki class their own episode.
Yes...I am still a bit sore about it. I don't know why, but I just am.