I said almost the same thing when I finished the game.
I now think that it would be better if the MC John is still the fake angel, and he sometimes uses Anabel as a tool to help him corrupt other people.
But having a prologue to the sequel where John finishes the job of having Anabel fully accept her life as a sex bomb would be nice. Like maybe the she-devil tells him he can't get another girl to play with until he completes his corruption of Anabel.