>>536757235
There's no reason to think the girl isn't the girl. There's a living shadow behind her as well as the little dark and light ghostly creatures on her so it's safe to say those are the shadow.
Sadly there's like no info in English on the folklore that inspired her so it's hard to make any good inferences beyond what's told.

The original is about a creature of shadow that waits at the bottom of stairs that lead to a perfect view, and most people who attempt cannot make it to the top and so as a shadow it cannot follow them there. Also something about achieving nirvana, it seems to be mostly metaphorical.

I'd say one of the most important things is that she's walking DOWN the stairs in the card art so presumably she's already made it to the top which is why the shadow creature has fused with her and why she is no longer blind but is looking at the viewer.

Her effect is one of duality. She can either destroy one card, or she can revive one from the GY. This reflects the symbolism from her art with her having a ghostly scythe and the white and black spirits with her.
Her banishing herself could be representing her reaching nirvana and its associated emptiness+lack of self but that seems like a stretch.
The important thing is that she's qute.