There's everything to love in this book. Sapphic dark fantasy, lonely women finding each other. The villain getting her happy ending...
But in the end it didn't really tick all the boxes for me. 
It is heavily focused on Mina's relationship with the witch whom she falls in love with before the witch does anything nice, they almost never speak (kindly) to one another before then... (or we just don't really get to see it as time goes by quite fast in the book). Stockholm syndrome, much?
I also felt a little unease when Mina engaged a nonconsensual kiss / 'suprise-kiss' (that ended up making the witch happy because it was "needed" for the witch to understand that Mina really did love her?)
The dark mystery behind the witch and why she needs companions was intriguing but not really that surprising.
I did appreciate the writing, the ambiance, the way it ended.