This took me a few tries to figure out but overall I enjoyed this book despite the repetitive pithy sayings, the horribly convoluted life lines and how the characters seem to hate and blame each other for the wrong reasons.
This starts in school with Caleb getting sick and loosing his powers (odd because demons can not get sick.) The shifters start turning into their animal forms but retain no common sense. They are also visited by a rider on a black horse with scales and plague ridden birdlike men that are covered in blood.
The weather is plague-like: a hailstorm with hail the size of baseballs, blood rain, a swarm of mosquitoes the size of bats and later a murder of crows that were resurrected from the dead to take vengeance on Caleb.
I think that of all the convoluted history the most important is Nick's mom Cherise is the daughter of a Sephiroth. She is pure of heart and it her inner light attracted Adarian Malachi. That means Nick has the blood of both Malachi and Sephiroth. He will be able to choose to be good or evil. Now that he knows maybe he will learn his Sephiroth powers and hopefully not develop multiple personalities.
Next Nick and his older brother are being tested to see which deserves the Malachi powers. Nick Has ti get berries that will cure Caleb and wake his mother.