User blog comment:Hidden Scorpius XI/Volume 3. Hypeness and Skepticism./@comment-11188061-20150623090113/@comment-24994749-20150624225602

That's where the trolling comes... We are all assuming Raven is the Masked Lady's name because is was listed in the voice actors credits at the end.

But the Masked Lady only spoke after removing her mask.

If the theory that the scene is a dream and Yang is imagining the Masked Lady to be her mum is correct, then the name listing could be for post-unmasking. And, since it's Yang's imagination, the face under the mask might not be correct.

So, the one who spoke is Yang's Mum, who was listed in the credits as Raven. The Masked Lady never spoke, so she never got listed.