Luna is a being comprised of all possible gods and goddesses of the moon, all of the moons she defeated and devoured when Oramus first created her.

To be clear, I do not mean that Luna took in all of the powers and abilities of the othermoons; I mean they are an actual part of her. Luna is multiple beings, all of whom are both Luna and not one another (in a way like the Trinity in Christian theology). They are all somewhat independent beings and personalities, both part of Luna and separate from her. Now, the "true" Luna - the glue that holds all of these disparate forms...