I am so sad that this series is over, but it is probably one of the best series I've read. The effort that the author put into these always amazes me when I read the author notes at the end to learn about the myths incorporated. 

I loved the character development for Hades and Persephone throughout the series and the development of their relationship as well. I felt like Persephone had a decent amount of growth in the last two or three books especially. I also loved her relationship development with all the side characters as well. This book definitely screams "found family trope" louder than the others in this series, however, I think it's a present theme throughout. 

I would have liked to learn more about Medusa, but I am thinking/hopeful the author is saving that for another series. I cannot wait to read about Aphrodite and Hephaestus.