3.75 - rounding up. 
 I would say that if you are of a particular religious persuasion and dislike anything that tweaks with certain aspects of the Creator, Lucifer, Angels, then you will have some issues here. 
 I love that kind of stuff, so those parts were my favorites. Definitely changes the dynamic of the battle between heaven and hell. 
 To be honest, the set-up of the whole world and Heaven/Hell were of more interest than the main characters. Not that they were bad, but they were a bit cold and prickly at first. They grew on me by the end. I did find Alex's reactions to be natural, especially given her family background. 
 There is a soulmate aspect, but this is not your typical Romance-soulmate book. In fact, it wasn't really romantic at all. Instead you have 2 people who flat out dislike each other, are antagonistic towards each other, and not in a "you know they're going to jump in the sack by chaper 12" way. It was a spin on the concept, and I liked it. 
 Villain was horrific but by the end you could see how he got that way. 
 This is not a standalone at all. The end is an ending of sorts, but I definitely need the next book.