I only hear or see people saying that Copia is the sun and Perpetua is the moon based off aesthetics, but like, Copia literally says he's the darkness (you'll be the light) and his albums match that. Compared to Skeletá, which is overall pretty uplifting thematically, it makes sense that Perpetua would be the light. I really like the aesthetics being switched between them, it makes for really fun character detail, it just makes me a little sad I dont see anyone else pointing it out.😔