The Gwok sisters represent, I believe, some of the most hamfisted character development ever seen in fiction. Gwok Fu was a one note horror, and to compensate, her little sister was depicted as a complete Mary Sue.
In fact, characterization seems to be a *huge* Achilles' Heel in ROCH. It's not that the characters were not memorable, but that their characterization was done with no subtlety at all. Everybody was painted in broad strokes.