I'm going to throw out pointless but funny theory, Greta is a Greek god trying to plant a seed of greed into the MC with talk of abusing the hotel's powers, you can tell from her eyes, pure evil
Nah, Greta is actually an unspeakable evil that is so powerful it will glitch out your game and manipulate your save files so that they all lead to the super secret route of using the hotel powers for her world domination mission. FOR SCIENCE!!