Overall Hallowed was a weak follow-up to an interesting, albeit flawed beginning to the series with Unearthly. Clara, the heroine, becomes practically unbearable in her irritating and waffling behavior. The focus of the novel is essentially Clara pining over whether to be with Tucker or Christian and what her "purpose" is. Be prepared to come to despise the word "purpose" by the end of the novel considering how often it is used.
Adding to the problem is that there was seemingly no plot, only Clara bemoaning her love life and crying for help every time she thinks a "Black Wing" is nearby. Considering the bad guys in these novels have yet to do anything seriously evil, I feel like there is a lot of hype for nothing. All of the "twists" are pretty eye-roll worthy and not at all surprising. Plus the reason for one person's death in the book is pretty pitiful, at least try and make the death a climax through a battle or something!
I appreciated that in Unearthly the religious element was largely limited, aside from the angels and "purpose". However, the Bible entries, God/He, "purpose" and other religious elements increased in Hallowed, much to my dismay. The fact that many of the entries were sexist just proved to be all the more aggravating. Most people won't be bothered, but I happen to be one of the few that are left annoyed by such inclusions. You can have a book with angels and limit the religious element, but Hand does not. She doesn't have to limit it but at what point does a book cross over into Christian fiction and require labeling as such?