Where IN the Underworld is the 15k armorer

I have done three out of the four quests there with a good team before we died due to the sheer difficulty of the quests, and I had yet to see any armor there that ppl keep speaking of. . .so where is it, and What do you have to do to get to him?

It's a big rumor and it's still unconfirmed till there is pictorial proof and the directions to this secret NPC that sells the other style of the outfits. I know of only 2 NPc at shiverspeak area that sells 2 and 2 of the outfit making 4 sets at 15k per piece.