Looking at my old 3rd ed book, at the top of Kruellagh's page it says, "Kruellagh, Archon of the Emasculators." However, in the description, it says she's from the Kabal of the Flayed Skull, and can only be used with them. In the flavor text on the side, it also says she's an Archon of the Flayed Skull, and then lists "The Emasculator" as one of her honorifics.
So... do we know who or what the Emasculators are? Do we know anything else about Kruellagh? There's a lot of stuff about the Flayed Skull in the new codex, but unless I missed it somehow, none of it mentions her. Are we just to assume that Vraesque deposed her? That doesn't seem right: she had a model, and he never even had stats. Also, we know some Kabals have more than one Archon (presumably arranged hierarchically in some fashion), so the existence of Vraesque doesn't mean that Kruellagh isn't still out there emasculating somewhere.
Has there ever been any reference to her since the original codex?