What does the masked figure represent in "The Masque of the Red Death"?

It has a threefold meaning:

First, it represents the red death itself, infiltrating itself in the castle with no idea from the courtiers.

With this, another meaning is ascribed:

First, the inevitability of Fate- No matter how much they ran, they still were followed by the red death.

Second, the vulnerability of man- Again, as much as they tried to control a situation by sheltering themselves, it went and found them.

Third: Fate itself- The courtiers tempted it, and she got them- The illness appeared in the castle, as guarded and as sheltered from it as it was.