group
I only liked the first series. Annabeth is my favorite character. Percy and Grover were poorly used in HoO, Jason is super overpowered and annoying, Piper was bland, Leo felt like an attempt to have another Percy but it fell flat, Hazel is too young for Frank, and the Greek/Roman gods thing was confusing. I never read the Kane Chronicles, liked Magnus Chase okay but it felt a little bland. Also Alex was a great concept that was very poorly executed. The best thing about Trials of Apollo is that it killed one of the seven, Apollo is super grating and the series should have focused on Meg.