Hades by Anemone. Various artbooks available here.
Keraunios by Lotus Workshop. Full artbook of eidolon designs here.
Hippolyta and Persephone by Lotus Workshop. Full artbook of champion designs here.
Persephone by Aracliare. Full artbook here.
Persephone by Renfri. Ko-fi shop for merchandise here.
Persephone by Beedok. To support her, you can buy her books.
Hades by Micah. You can support them by buying their co-authored books.
Madalithea and Cedalion by H.D. Thorn. You can support her when she has something available on her Itch page.
Hephaestus, Persephone, and Hades by Mango. Full artbook here as well as a ko-fi shop for physical stickers and keychains. They also have a Patreon.
Demeter by WindyGria. You can support her on Ko-fi and buy her comics on Itch.
Sister Madalithea by Cirice Gray. The character is original to Cirice, but has a prominent role in The Persephone Effect. You can support her on Itch and Patreon.
Gunmetal Olympus / Hades Calculus 