And I know it was probably inevitable, but the more Debra starts to accept Dexter's serial killing ways, the more it feels like the season is losing the charge and momentum it once had.
What Deb has "accepted" is things going back to the way they were: Dexter doing what he does, and Deb not knowing about it or being a part of it. Dex just shrugged and said okay, but they're both going to learn very quickly how delusional it is to think that possible. Deb is inextricably a part of Dexter's deeds now. Not knowing the specifics of what he's up to doesn't mean she won't still be covering for him (and herself), it just means it will be more difficult for her to do it effectively.