I wasn't sure what to think of this book. It's a spin-off of Armentrout's YA Lux series (of which Obsidian is the first book). But Obsession is aimed at a more adult market and focuses on the Luxen's enemies - the Arum. 
 I enjoyed the writing. It was fun, sexy and an interesting read. It was cool seeing the opposite side of the coin so to speak and see just how similar the Arum and Luxen are - and who their true enemies are. 
 The switching POVs added to the overall feel of the novel - and I enjoyed it more for that. Hunter and Serena are a good match and I liked getting to read their story.