Any persons? I haven't tried with other people because by the time I got to know how to use the device, it was during my battle with Kerghan.
ah yes. I actually fought Kerghan. He was actually easier than those damn ore golems in the BMC, but once his percentage gets low enough he'll just start regenerating and my attacks couldn't get through his shield. I think this is an example of the downside of this completely customizable world thingy; they can't make the last boss too hard or thieves and diplomats would just die. The VD is simple- just use it like any other item. DOn't bother trying to kill Kerghan normally. It doesn't work. Trust me.
I whacked him till he retreated to the regenarative shell nasrudin talked about must be done like that I think.