Merlumina is the guardian of the second Pure Heart, but very little is known about her. She made it her duty to pass on the legend of the Pure Hearts and the Purity Heart to the four heroes, and does so with a bit too much enthusiasm. Despite only being around for a short time, she talks a fair amount in her scene, even going as far as to put Mario to sleep with her long, overly drawn out story.

It's difficult  to describe a fitting voice for Merlumina, as not much is known about her personality, though I think it should be fairly old sounding, with some eccentricity.