Responses
It's called progression of plot, the cue for Yuri's personality has always been around since day 1 chapter 1, it has worsen obviously so and should have been something a reader should know if they read the story properly instead of focusing on the superficial things. Yuri was never the good person, nor is the teacher, this isn't a "yanfere route" it's called mental health problems.
it’s really hard defending yuri after reading these recent chapters. i used to actually like him but he’s becoming too possessive. is author going for yandere route , lmao?? (￣∇￣")?!