I really enjoyed this book. 
 Ileni is an inspired main character, she is not at all a damsel in distress but takes matters into her own hands. She has been sent to tutor the assassins, who live in a system of caves, in magic, the last two tutors were killed and she has been sent to find out how/why - the reason she was sent was that her magic is fading and she is thus expendable. 
 But she is not stupid. She is cautious and wary. Faced with these harrowing circumstances she does not crumble but keeps her head held high and manages as best as she can. I love that she wasn't depicted as not being afraid, because that wouldn't be plausible in these circumstances, but rather doesn't let the fear win. 
 I love that the assassins were written as brutal and unforgiving, many authors romanticize assassins and that's fine but I enjoyed how Ileni reacted to the killing and I admired her audibly sticking to her views even when she was surrounded by hundreds of them. 
 I also really enjoyed the assassins world, how they have all these set beliefs fed to them by The Master and how adherent their unwavering loyalty was, their different views and all. 
 (view spoiler)[Now that Ileni has left the caves I am excited to see the world building beyond the caves. (hide spoiler)]