User blog comment:SayuriDarling/The Trials of Apollo Official Discussion/@comment-5166047-20151022233441

What I hope to see in the series:

-Solangelo development

-Rachel's, Ella's, and Tyson's quest for the Sibylline Books

-Helios/Sol, Selene/Luna, and Eos/Aurora

-Eurus

-The return of Bob and Damesen

-The return of Leo, Calypso, and Festus

-Alabaster and Claymore

-Egyptian magicians (preferably from the 21st nome)

-Norse demigods/einherjar

-Ganymede

-Hebe and  Eilethyia

-Hestia and Dionysus returning to Camp Half-Blood

-Jason as Pontifex Maximus

-other minor Greco-Roman

In all honesty I don't know how many of these would actually appear but it's not like a fan is not allowed to speculate