Is there is a limit on how far can the characteritics of a fictional setting be copied?

When a story/game/etc. has a character named Zagreus with the title "Prince of the Underworld", and Melinoë with the title "Princess of the Underworld", is this story a derivative of the Hades I & II games? Note that both Zagreus and Melinoë aren't original creations of these games. They are from mythology & folklore, but they barely appear in ancient documents (Zagreus is basically just a name in ancient myths, and Melinoe only appears in a few Orphic Hymns)