I apologize for not being able to spell things accurately at the moment as I don't have the books near me but I have a question. You call the gods by full names from time to time. Like Peresephone Praxidike and Hades Aidoneus *insert the word that begins w

The names were a mix of creative license and historical knowledge. They were epithets for the gods, most of them largely featured in the Homeric and Orphic hymns.

Aidoneus was used in the Homeric Hymn to Demeter because the poem was written in iambic hexameter, and the flow of Aidoneus was easier to alliterate than Aides (Hades). And I just like it better as a name. So I mashed them together to come up with Hades Aidoneus Chthonios Polydegmon, which, if you translate them out from epithets literally means “The Unseen Lord of the Earth Below Who Receives Many”

For Persephone, I wanted to give her name two middle epithets. One to represent who is is above (Karpophoros) and one to represent who she is below (Praxidike).

Chthonios is an epithet for whoever lives in the Underworld. In my telling, you get that as your surname once you consume anything there.

Hope this helped.