[@Dusksong]

[@RedDusk]

I think I figured out a solution:

[hider=Solution]
Persephone’s curse is in the form of a tattoo, or rather birthmark, it is something that changes with the era she finds herself in. In every era it is below her skin and permanently unreachable. Currently it looks like tribal pain on her ankle in the shape of a Lion. Once literacy is more common and so forth it begins with the word Superbia, which is found on her ankle. This is permanently there, however it starts very small. As the curse consumes her life force, it grows to fit her entire calf, with more tattoos appearing along with it. Flowers, waves, tears, stars. Many things begin to consume her, but the most notable are the following seven words, or symbols once more depending on the era: “Luxuria, Gula, Avartia, Acedia, Ira, Invidia, and finally Superbia are the symbols. While the Snake, Pig, Frog, Goat, Bear, Dog and Lion are the symbols during Tribal eras and time periods. Superbia (Lion) and Ira (Bear) taking her legs, Invidia (Dog) and Acedia (Goat) her arms, Gula (Pig) her stomach and Luxuria (Snake) her throat. When she is fully consumed, she will be fully consumed with the sins she bears for everyone. With minor usage, only the seven words appear or animals, the rest of her life force being drained is what brings all of the surrounding art, as it were.[/hider]

This way, during tribal times the sins are represented through the animals that have represented them in the past, animals are a common thing in this time period so it shouldn't be a problem - even if not everyone understands it. And during this era it looks more like tribal paint but is trapped underneath her skin. Explained as far as she knows, as a birthmark. Thanks for the heads up!