I can't get enough of Nadia and Diesel! And now we get new characters like Hiro, Jacky and Logan, and we get more in depth with Diesel's other personalities. Soul Finder was even more grittier than Soulless, and it was a bonus to have a lot of things be revealed like Diesel's memories/thoughts, the truth about the Soulless', the drug, and who are the evil guys and their plans. 
 The way it ended in a cliffhanger, (Diesel!),I honestly can't wait for the next book, Soul Reaper. I hope that a cure can be found, and that Nadia and Diesel end up together, and that all of the that popped up will be answered.