This 5th installment provided some resolve to Persephone  and hades situation. They grew a bit closer. But Persephone and hades weren’t really big players in the story. This volume provided a lot Of character information dumping for all the extra gods and goddesses. 

There is one large event from Persephone past that is revealed which I believe is setting up future volumes. This volume ends on a cliffhanger and it’ll be a long 6 months to find out what happens next!