This book (and this series in general) felt so classic Shadowhunters to me and I loved it. 

I'm usually not a fan of love triangles at all but the way Cassie Clare writes them I can't help but love them (even if they do appear a lot). Like the Jem/Tessa/Will triangle, whilst I was rooting for James and Cordelia and just waiting for them to get back together, I truly felt for Matthew and my heart broke when he was speaking to James about loving Cordelia and the reasons why. 

I thought it was a great end to the series, and also helped build up backstory for Malcolm which I enjoyed getting that final piece of context for his story and what really pushed him over the edge with his Shadowhunter hatred. 

James' character was dealt with fantastically, and I think in this book Lucie finally got the credit she deserved as she fully submitted to her powers with Jesse's help. Wish I had time to reread the first two books before I read this one (two year wait??) to maximise the emotional impact, but at this point I don't know if there's a Shadowhunter book I couldn't love.