jarbear said:
Just having the whispers doesn’t really “reveal” or overtly hint at anything. Why? This is a Dark side place, we as the audience know that! So having those whispers isn’t really pointing “Hey, we are hinting something, can’t you tell?!”

Agreed.

poppasketti said:
The way I looked at it with what I have currently is that the hood could be Palpatine himself or Rey in a Palpatine cloak (as she appears in TROS), and the idea is just to tease the imagery.

Although it would be less subtle, you could illustrate that by having the hood quickly morph from “Evil Rey” to normal Rey when Palpatines silhouette approaches.