Dark but captivating
I really enjoyed a lot of this book. But the title is legit, it's dark. Why? Because you have 16 yr old triplets training, since they were 6, to sharpen their special abilities in order to kill their other sisters--so that they can claim the crown.
But most of this book isn't the fight. It's more about getting to know each sister and their lives. Some have said it's boring and lacks action at the beginning, but I enjoyed the slow weaving of information.
This would definitely be compared to an upper PG13 movie, for anyone who wants to be choosy about their reads, especially for younger readers. There are mentions of intimacy even if it's not in detail. There is almost no profanity though.