As an MC, Bakarina is infinitely better than Rei (thankfully manga Rei has more personality than novel Rei).
Ehh, I honestly disagree. I feel Bakarina get more and more boring as the story goes on, while Rei gets better and better.
It’s okay to disagree! It opens up more room for discussion. I found Rei to be a rather bland, empty shell of a character. In my opinion, her not so defined personality is good for allowing the reader to insert themselves into the character. But I personally enjoy characters with strongly defined personalities, such as Bakarina. Why do you feel that Rei gets better as the story progresses? Do you think Rei experiences any character growth and how?
Did we read the same thing? Like, I don't see how in any way, shape, or form is Rei bland, empty shell, or a self insert. In matter of fact, I'm pretty sure most people complaint about her in both WN and Manga is that her personality is too much for them, I wouldn't call that bland exactly.
As for the comparison with Bakarina, for me after the first few episodes she is pretty much just become a nice, dense, idiot who can't take a hint. Rei on the other hand is like @Hylarn said a sadomasochistic goofball who is more cunning than she seems, and as the series goes on we actually learn why she is that way.