These masks don't belong to the Goddess.
試遊体験ブースに、ゲーム内に登場する「神の力を宿した""面"
It's not 'Imbued with the power of the Goddess' but of the 'gods'.
It must be a translation error?
Because now this makes sense. It's not the masks belonging to the Goddess but to the Gods.
The masks are imbued with the power of the ancestral deities who were the gods of the mountains that caused all of this misfortune. After defiling the Goddess, their masks(powers) were stolen by the Defiled Goddess's underlings, the Seethe.
The Seethe drop orbs, which seem to be the Goddess's powers.(if we look at the talismans)
This power is used to carve the spirit path and to equip the masks. But why?
Because she seems to be the only acting deity now and doesn't need to be 'resurrected'?
Yoshiro is clearly divine in nature but it might be a shrine maiden thing as they are said to become the Goddess during the Kagura. Naturally, she will become defiled as the Goddess was.
The mask Soh wears...must belong to the Goddess.
Because when one wears the mask, you live as the messenger of said deity.
I think the reason the term 'The Maiden' is used is because she's the chosen shrine maiden. Here it uses 'designated shrine maiden' but in english, simply saying 'The Maiden' is meant to imply she's the chosen one.
Summary:
The villaers all become messengers of their ancestral deities during this ceremony.
Soh's ancestor is the Goddess as she becomes the messenger of the Goddess and dons her mask.
Yoshiro's lineage made a vow alongside these ancestral deities.
The only way I can figure out what's going on in this game is to get a hold of good Japanese translations on the lore.