It could work, although whips are portrayed as more of a weapon that is used at opportune times to disarm an opponent or to entangle their limbs than to inflict constant damage the way the guild wars combat style works.
Perhaps a class that wields a whip in a secondary hand and uses it after other skill combinations have been fulfilled to disarm or disable a foe (through a hex or condition, perhaps?). I haven't played castlevania, but something that uses a whip that comes immediately to my mind is some kind of witch hunter with a brace of silver-bulleted pistols, a stake, and a whip
Or maybe you are getting at a BDSM profession for GW, you sly dog, you.