now that this arc is over, I am probably in the minority that really liked it. We got to see a lot of things that I thought we weren't gonna see for a long while.
This was the first time we saw a lot of good character growth. We saw the three girls be weak, and deal with a situation that can't be solved with just violence. Someone who can get in their head and they have to use actual communication to solve the issue at hand.
We also saw one of Unoki's main bullies and I understand why the way he is now. Imagine having a bully like that, it's bound to fuck up your sense of self worth and just question if anybody really likes you. I was hoping to see one of his bullies to get a better understand of Unoki's past.
As for Youdou, she's a whole lot of nutcase, but I've seen a yandare like her before. The closest I can think of is Renner from overlord. How she obsesses over Climb, but doesn't really see Climb as a love interest. I think Youdou thinks of Unoki more as a plaything that she has grown attached to, like a teddy bear she has had since she was a child. Her inclusion was interesting, but I loved to hate her, and seeing from the comments from all the chapters, I think the mangaka really created a character that people really hated. I think that was the entire point, you were supposed to hate her.
I really liked how this arc just gave the whole story a really jarring jolt.