Looking through the achievs for the cata dungeons and i found this guys name pop up in the Vortex pinnacle and the stonecore. Any one have a clue about who it is or if its just a placeholder? http://db.mmo-champion.com/c/42333
No one can say if it's a bug yet EbonChampion, as Vortex Pinnacle has never been open for testing.
They've had one build to correct the Vortex Pinnacle achievement since it was first put into the alpha and they didn't correct it, so that suggests it's intended that she exists in both.