Theory:
What if Blythe was truthful when they said they were inside Y/N's brain? Rather than it being AI, what if it was drugs? After all, pills were shown in menu screen.
Blythe and Blythe? are the opposite sides of the drug. Everything is an illusion. Blythe didn't want Bunny to fall sleep because the drugs would wear off effect. At the same time, it doesn't explain how Blythe was able to change things by will, such as suddenly disappearing. After all, drugs aren't stable. But what if it is there is an AI in bunny's brain, but the AI puts drugs into their system? Or what if he is an alien? I can only wonder ^-^